display avatar with closed eyes when sleeping

Display the sleeping version, when users are in the inn.

CAUTION: For this to work, this pull request will have to be merged first: https://github.com/HabitRPG/habitrpg-shared/pull/269
Otherwise the _sleep images are missing. ;)
Merge pull request #3837 from vIiRuS/patch-4

display avatar with closed eyes when sleeping