Fix hang on missing state update handler

Author: sapir

crates/bevy_ecs/src/schedule/state.rs

@@ -132,12 +132,15 @@ impl<T: Resource + Clone> Stage for StateStage<T> {
                 {
                     enter_next.run(world, resources);
                 }
-            } else if let Some(update_current) = self
-                .stages
-                .get_mut(&current_stage)
-                .and_then(|stage| stage.update.as_mut())
-            {
-                update_current.run(world, resources);
+            } else {
+                if let Some(update_current) = self
+                    .stages
+                    .get_mut(&current_stage)
+                    .and_then(|stage| stage.update.as_mut())
+                {
+                    update_current.run(world, resources);
+                }
+
                 break;
             }
         }