[IMPR] simplify code in treat_disamb_only
[IMPR] simplify code in treat_disamb_only

- move code out of try statement in treat_disamb_only
- remove include = False statement; include is False by default

Change-Id: I2c4946299df5ed8ad2e5befdb080eb4897e11e36

wikimedia/pywikibot-core,wikimedia/pywikibot-core