widget: fix the abi break.
widget: fix the abi break.

Widget type string should be all lower-cases!

This acutally was caused in 7b10fdb8f39c3b36f575dd22d26a1efe6ecd28ec

@fix

FlorentRevest/Elementary,rvandegrift/elementary,tasn/elementary,rvandegrift/elementary,FlorentRevest/Elementary,FlorentRevest/Elementary,FlorentRevest/Elementary,rvandegrift/elementary,tasn/elementary,tasn/elementary,tasn/elementary,rvandegrift/elementary,tasn/elementary