[IMPR] remove superfluous assignment to a instance variable
[IMPR] remove superfluous assignment to a instance variable

self.hiddentemplates is a instance variable which might be expanded
in loadHiddenTemplates() method. A reassignment is not necessary.

Change-Id: I79bad15e6000c83d3b5f5249d68bc1d3c78edf77

h4ck3rm1k3/pywikibot-core,smalyshev/pywikibot-core,Darkdadaah/pywikibot-core,npdoty/pywikibot,wikimedia/pywikibot-core,Darkdadaah/pywikibot-core,hasteur/g13bot_tools_new,icyflame/batman,npdoty/pywikibot,h4ck3rm1k3/pywikibot-core,jayvdb/pywikibot-core,jayvdb/pywikibot-core,darthbhyrava/pywikibot-local,hasteur/g13bot_tools_new,happy5214/pywikibot-core,wikimedia/pywikibot-core,magul/pywikibot-core,happy5214/pywikibot-core,PersianWikipedia/pywikibot-core,hasteur/g13bot_tools_new,magul/pywikibot-core