[IMPR] Improvements for WelcomeBot.run method
[IMPR] Improvements for WelcomeBot.run method

- dedent else clause after continue
- calculate welcomed_count from welcomed_users list length
- order welcomed number messages and shortcut it
- remove continue after for loop has finished

detached from Iff53f3818f

Change-Id: I70cc64c15bcdf97d162e59870dbb7f8b9efa4899

PersianWikipedia/pywikibot-core,wikimedia/pywikibot-core,wikimedia/pywikibot-core