Don't send compositor's global key bindings to the input method

Although weston_compositor_run_key_binding() is called when the current
keyboard grab is default_grab or input_method_grab, swallowing the key
event is processed only on default_grab. As a result key events that
should be swallowed are sent to the input method unexpectedly.

For example, when a user press `Super + s` on weston-editor to take a
screen shot, `s` will be unexpectedly entered to the text area.
I confirmed such behaviour with weston-simple-im and fcitx5-5.0.10.
It doesn't occur with weston-keyboard because it doesn't install
keyboard grab.

Signed-off-by: Takuro Ashie <ashie@clear-code.com>

libweston/bindings.c

@@ -310,8 +310,8 @@ weston_compositor_run_key_binding(struct weston_compositor *compositor,
 			/* If this was a key binding and it didn't
 			 * install a keyboard grab, install one now to
 			 * swallow the key press. */
-			if (keyboard->grab ==
-			    &keyboard->default_grab)
+			if (keyboard->grab == &keyboard->default_grab ||
+			    keyboard->grab == &keyboard->input_method_grab)
 				install_binding_grab(keyboard,
 						     time,
 						     key,