bugfix: don't crash when saving screenshots with no file extension
bugfix: don't crash when saving screenshots with no file extension

CID 1132744

tizenorg/platform.upstream.enlightenment,tizenorg/platform.upstream.enlightenment,FlorentRevest/Enlightenment,tasn/enlightenment,FlorentRevest/Enlightenment,tasn/enlightenment,tizenorg/platform.upstream.enlightenment,rvandegrift/e,rvandegrift/e,tasn/enlightenment,rvandegrift/e,FlorentRevest/Enlightenment