I was running weblinkchecker.py for whole cswiki (job was submited to the grid at Sun, 20 Nov 2016 16:54:24 GMT) because I wished to have a list of deadlinks. This may correspond with the UA (because I used script named weblinkschecker.py). I trusted this script it won't do anything wrong because this script was and still is in standard core package. I also use 3.0-dev version of pywikibot and Python 2.7.6.