Fixed a not needed ';' in GDScript sample code (#4713)

getting_started/step_by_step/your_first_game.rst

@@ -864,7 +864,7 @@ Note that a new instance must be added to the scene using ``add_child()``.
 
     func _on_MobTimer_timeout():
         # Choose a random location on Path2D.
-        var mob_spawn_location = get_node("MobPath/MobSpawnLocation");
+        var mob_spawn_location = get_node("MobPath/MobSpawnLocation")
         mob_spawn_location.offset = randi()
 
         # Create a Mob instance and add it to the scene.