upload.py: remove "Do you want to change this description?" when it's empty
upload.py: remove "Do you want to change this description?" when it's empty

- If no description, ask if user want to add one or quit, and loop until one is filled.
- If self.verifyDescription, ask if user want to change it or continue.
- If neither of them, continues

Bug: T163108
Change-Id: Iec43845e293721aee70d8f1129b323d7fbceb8b8

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