Fix duplicate task tags
Fix duplicate task tags

updateTagList returns any tags with matching names regardless
of tagType so if a tag was added to a task that had both
'challenges' and 'tasks' tag types it would appear twice.

maproulette/maproulette2,maproulette/maproulette2,Crashfreak/maproulette2,mgcuthbert/maproulette2,Crashfreak/maproulette2,mgcuthbert/maproulette2,maproulette/maproulette2