Revert "wayland/window-configuration: Fix maximized check in fixed size check"

This reverts commit 8c6b3e03.

The change, while correct, caused a behavior change in mutter, which exposed a bug in gtk and potentially other clients due to no longer including an explicit size in focus change configures. Since the only known observable bug this commit was fixing is not present in 41, just revert it.

See #2091 (closed)