clients/presentation-shm: Bind to xdg_wm_base version 1

It was binding to any advertised version, but it can't actually work
with version 4 (because it doesn't handle the new configure_bounds
event).

Other sample clients in the tree are hard-coding version 1, so do the
same here.

Fixes: 6d9fda71 ("clients/presentation-shm: use xdg_shell instead of wl_shell")
Signed-off-by: Michel Dänzer <mdaenzer@redhat.com>