[cleanup] Remove pre mw 1.14 code
[cleanup] Remove pre mw 1.14 code

Pywikibot supports mw 1.14+
https://www.mediawiki.org/wiki/Manual:Pywikibot/Overview

- remove pre mw 1.14 code found in api.ParamInfo.parameter()
- check whether 'parameters'in module only once

Change-Id: I66f00d28c205d2bb1dcf6071592b75d544f02f5c

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