Contacts not readable in Opera

[summerm78]

Steps to reproduce

1. Upgrade to Contacts 2.1.0
2. Login and open Contacts

Expected behaviour

Contactlist should be readable.

Actual behaviour

Contactlist is resized to 3 characters

Server configuration

Operating system:
Linux 3.10 (sorry, not more informations because it is a managed plattform)

Web server:
apche2

Database:
mysql 5.5.56

PHP version:
7.1.14

Nextcloud version: (see Nextcloud admin page)
13.0.0

Contacts version: (see Nextcloud apps page)
2.1.0

Updated from an older Nextcloud or fresh install:
Update from 12.5.0

No errors have been found.

Are you using external storage, if yes which one: local/smb/sftp/...
No

Are you using encryption: yes/no
No

Are you using an external user-backend, if yes which one: LDAP/ActiveDirectory/Webdav/...
No

Client configuration

Browser:
Opera 51.0.2830.26, always full-screen
Cache cleanded and private tab

Operating system:
Fedora 27
Windows 10

[skjnldsv]

Duplicate of #453