shell: Do not remove input panel layer when locked
shell: Do not remove input panel layer when locked

Do not remove the input panel layer from the layer list when the
shell is locked in hide_input_panels().

https://bugs.freedesktop.org/show_bug.cgi?id=56543

Signed-off-by: Jan Arne Petersen <8c3575d1e692bfe9fd3220cb3956503cdd270f15@openismus.com>

udoprog/weston,mchalupa/weston,giucam/weston,xorgy/weston,Fantu/compositor-spice,Fantu/compositor-spice,Gnurou/weston,eyolfson/weston,xorgy/weston,kwm81/weston,krezovic/weston,sir-murray/weston,mchalupa/weston,Tarnyko/weston-xdg_surface_present,kwm81/weston,udoprog/weston,giucam/weston,Gnurou/weston,jonnylamb/weston,sir-murray/weston,krezovic/weston,Fantu/compositor-spice,jonnylamb/weston,eyolfson/weston,Tarnyko/weston-xdg_surface_present