Reapply "unload immediate"

This reverts commit b0f445e415f9e0b19131ee99c0d67f16630235d4.

NewHorizons/Handlers/PlanetCreationHandler.cs

@@ -47,7 +47,8 @@ namespace NewHorizons.Handlers
             {
                 foreach (var bundle in StreamingManager.s_activeBundles)
                 {
-                    StreamingManager.UnloadStreamingAssets(bundle.assetBundleName);
+                    // save memory NOW instead of next frame when other stuff has loaded and taken memory
+                    bundle.UnloadImmediate();
                 }
             }