[bugfix] hash for LogEntry should be unique
[bugfix] hash for LogEntry should be unique

Per https://docs.python.org/3.4/reference/datamodel.html#object.__hash__ :
"it is advised to somehow mix together (e.g. using exclusive or) the hash
values for the components of the object that also play a part in comparison
of objects."

Bug: T173688
Change-Id: If124e1bf61e23543b8972ff65f75094c0bdd255c

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