[ARP] No module named 'show_dhcp6relay_counters' - in case when run cmd "sonic-clear arp"

[ppikh]

Description

Error in output in case when run cmd "sudo sonic-clear arp"
failed to import plugin clear.plugins.dhcprelay: No module named 'show_dhcp6relay_counters'

Steps to reproduce the issue:

1. Run cmd "sudo sonic-clear arp"
2. Check output

Describe the results you received:

Error "failed to import plugin clear.plugins.dhcprelay: No module named 'show_dhcp6relay_counters'" in output

root@r-panther-13:/home/admin# sudo sonic-clear arp
failed to import plugin clear.plugins.dhcprelay: No module named 'show_dhcp6relay_counters'
10.210.24.1 dev eth0 lladdr 00:00:5e:00:01:01 ref 1 used 2/0/2 probes 4 REACHABLE

*** Round 1, deleting 1 entries ***
*** Flush is complete after 1 round ***

Describe the results you expected:

No error "failed to import plugin clear.plugins.dhcprelay: No module named 'show_dhcp6relay_counters'" in output

Output of show version:

SONiC Software Version: SONiC.master.202-7d40384c5_Internal
Distribution: Debian 10.11
Kernel: 4.19.0-12-2-amd64
Build commit: 7d40384c5
Build date: Mon Oct 11 11:32:48 UTC 2021
Built by: sw-r2d2-bot@r-build-sonic-ci03-244

Platform: x86_64-mlnx_msn2700-r0
HwSKU: Mellanox-SN2700
ASIC: mellanox
ASIC Count: 1
Serial Number: MT2020T04244
Model Number: MSN2700-CS2FO
Hardware Revision: A2
Uptime: 09:03:13 up 23 min,  1 user,  load average: 1.37, 2.56, 2.09

Docker images:
REPOSITORY                    TAG                             IMAGE ID            SIZE
docker-dhcp-relay             latest                          438ccae1309f        427MB
docker-syncd-mlnx             latest                          f86a55649300        998MB
docker-syncd-mlnx             master.202-7d40384c5_Internal   f86a55649300        998MB
docker-sflow                  latest                          e125260b39d3        427MB
docker-sflow                  master.202-7d40384c5_Internal   e125260b39d3        427MB
docker-teamd                  latest                          0874f41ac316        426MB
docker-teamd                  master.202-7d40384c5_Internal   0874f41ac316        426MB
docker-nat                    latest                          5ef490b4a749        429MB
docker-nat                    master.202-7d40384c5_Internal   5ef490b4a749        429MB
docker-sonic-mgmt-framework   latest                          4cb3f60d1da4        569MB
docker-sonic-mgmt-framework   master.202-7d40384c5_Internal   4cb3f60d1da4        569MB
docker-router-advertiser      latest                          2acc4a8f0888        414MB
docker-router-advertiser      master.202-7d40384c5_Internal   2acc4a8f0888        414MB
docker-platform-monitor       latest                          a95dd32e1397        748MB
docker-platform-monitor       master.202-7d40384c5_Internal   a95dd32e1397        748MB
docker-lldp                   latest                          f43c1ebf597f        454MB
docker-lldp                   master.202-7d40384c5_Internal   f43c1ebf597f        454MB
docker-snmp                   latest                          c23bd2bbc1ed        456MB
docker-snmp                   master.202-7d40384c5_Internal   c23bd2bbc1ed        456MB
docker-database               latest                          8ed36953ba07        414MB
docker-database               master.202-7d40384c5_Internal   8ed36953ba07        414MB
docker-orchagent              latest                          a2798df0a9b2        444MB
docker-orchagent              master.202-7d40384c5_Internal   a2798df0a9b2        444MB
docker-macsec                 latest                          7b4d25bd1cbc        429MB
docker-macsec                 master.202-7d40384c5_Internal   7b4d25bd1cbc        429MB
docker-sonic-telemetry        latest                          efd3000adcbf        502MB
docker-sonic-telemetry        master.202-7d40384c5_Internal   efd3000adcbf        502MB
docker-fpm-frr                latest                          dae6de605d2c        444MB
docker-fpm-frr                master.202-7d40384c5_Internal   dae6de605d2c        444MB

Output of show techsupport:

[sonic_dump_r-panther-13_20211012_085809.tar.gz](https://github.com/Azure/sonic-buildimage/files/7328463/sonic_dump_r-panther-13_20211012_085809.tar.gz)

Additional information you deem important (e.g. issue happens only occasionally):

[shlomibitton]

Fix PR: #8991