[bugfix] Don't break watchlist.py for InvalidTitle
[bugfix] Don't break watchlist.py for InvalidTitle

Instead of breaking the script print the error message.

Bug: T106954
Change-Id: Ie8ca8fa4c66d724b998be72b53a389a402c55e7e
npdoty/pywikibot,h4ck3rm1k3/pywikibot-core,hasteur/g13bot_tools_new,magul/pywikibot-core,hasteur/g13bot_tools_new,npdoty/pywikibot,jayvdb/pywikibot-core,Darkdadaah/pywikibot-core,wikimedia/pywikibot-core,magul/pywikibot-core,wikimedia/pywikibot-core,jayvdb/pywikibot-core,happy5214/pywikibot-core,hasteur/g13bot_tools_new,h4ck3rm1k3/pywikibot-core,happy5214/pywikibot-core,PersianWikipedia/pywikibot-core,Darkdadaah/pywikibot-core