delete.py: do not attempt to delete not-existing pages
delete.py: do not attempt to delete not-existing pages

Avoid to process not existing pages when deleting.

Bug: 69134
Change-Id: I593a202fb336bee9e5cbeb27f4601c7c7e80e903

happy5214/pywikibot-core,h4ck3rm1k3/pywikibot-core,Darkdadaah/pywikibot-core,hasteur/g13bot_tools_new,happy5214/pywikibot-core,valhallasw/pywikibot-core,PersianWikipedia/pywikibot-core,icyflame/batman,TridevGuha/pywikibot-core,xZise/pywikibot-core,magul/pywikibot-core,VcamX/pywikibot-core,trishnaguha/pywikibot-core,jayvdb/pywikibot-core,npdoty/pywikibot,magul/pywikibot-core,emijrp/pywikibot-core,h4ck3rm1k3/pywikibot-core,smalyshev/pywikibot-core,hasteur/g13bot_tools_new,hasteur/g13bot_tools_new,jayvdb/pywikibot-core,darthbhyrava/pywikibot-local,wikimedia/pywikibot-core,Darkdadaah/pywikibot-core,wikimedia/pywikibot-core,npdoty/pywikibot