Clean up obsolete code in cosmetic_changes.py
Clean up obsolete code in cosmetic_changes.py

The exception handling is done in CurrentPageBot._save_page().

Change-Id: I082f49c7df2edf8910722910cca20ca486e575fe

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