movepages.py: deprecation of -pairs fails to recognise -pairsfile
movepages.py: deprecation of -pairs fails to recognise -pairsfile

Bug: T139243
Change-Id: Iaa0f8c174caf2438a5b6398e4493cba6b2f04aa9

happy5214/pywikibot-core,hasteur/g13bot_tools_new,magul/pywikibot-core,jayvdb/pywikibot-core,Darkdadaah/pywikibot-core,Darkdadaah/pywikibot-core,wikimedia/pywikibot-core,hasteur/g13bot_tools_new,npdoty/pywikibot,happy5214/pywikibot-core,PersianWikipedia/pywikibot-core,jayvdb/pywikibot-core,hasteur/g13bot_tools_new,npdoty/pywikibot,wikimedia/pywikibot-core,magul/pywikibot-core