[scripts] remove duplicate script copying for nbrshow (sonic-net#517)

* [scripts] remove duplicate script copying for nbrshow

Signed-off-by: Ying Xie <ying.xie@microsoft.com>

* also fix mmuconfig location to make the list in alphabetic order

setup.py

@@ -57,7 +57,6 @@
  'scripts/decode-syseeprom',
  'scripts/dropcheck',
  'scripts/ecnconfig',
- 'scripts/mmuconfig',
  'scripts/fast-reboot',
  'scripts/fast-reboot-dump.py',
  'scripts/fdbclear',
@@ -66,6 +65,7 @@
  'scripts/intfutil',
  'scripts/intfstat',
  'scripts/lldpshow',
+ 'scripts/mmuconfig',
  'scripts/nbrshow',
  'scripts/neighbor_advertiser',
  'scripts/pcmping',
@@ -80,7 +80,6 @@
  'scripts/route_check_test.sh',
  'scripts/sfpshow',
  'scripts/teamshow',
- 'scripts/nbrshow',
  'scripts/warm-reboot',
  'scripts/watermarkstat',
  'scripts/watermarkcfg'