[FIX] gamification: compute badge stats wihtout error

Since 960360a, when computing badge stats, a datetime was compared to a
string leading to a traceback.  e.g. when clicking in employess >
badges.

Also, due to a typo, the compute method was assigning the stats result
to the wrong attributes.  e.g. 'stats_my_this_month' instead of
'stat_my_this_month'.

With this commit, the above mentioned issues are fixed and a test is
covering these issues to avoid regression.

0 files changed, 0 insertions, 0 deletions