compositor-wayland: Convert fullscreen flag to bool

Signed-off-by: Armin Krezović <krezovic.armin@gmail.com>
Reviewed-by: Quentin Glidic <sardemff7+git@sardemff7.net>
diff --git a/compositor/main.c b/compositor/main.c
index 320305c..8028ec3 100644
--- a/compositor/main.c
+++ b/compositor/main.c
@@ -1577,7 +1577,7 @@
 	config.cursor_size = 32;
 	config.cursor_theme = NULL;
 	config.display_name = NULL;
-	config.fullscreen = 0;
+	config.fullscreen = false;
 	config.sprawl = false;
 	config.use_pixman = false;