[L10N] Enabled using of checkimages.py on Serbian wikis
[L10N] Enabled using of checkimages.py on Serbian wikis

Change-Id: If83b0b6f1b632fa8c5d059f7a1b2488f2fa04a5a

wikimedia/pywikibot-core,wikimedia/pywikibot-core,PersianWikipedia/pywikibot-core