[IMPR] Shorten the loop in add_text.py
[IMPR] Shorten the loop in add_text.py

- if putText is not True add_text function may return earlier
- in result the next if statement needs only to check whether
  text != newtext
- the while loop is only needed for 'b'rowser choice, so shorten
  the loop here too.

Change-Id: Ie5002dec8e23b15a78c8f6fd7b9351e3cfe0c09d

wikimedia/pywikibot-core,wikimedia/pywikibot-core