Revert "Fix wrongly rewritten get_app_module"

This reverts commit 18db7a08.

aleksis/core/util/core_helpers.py

@@ -73,17 +73,17 @@ def get_app_packages(only_official: bool = False) -> Sequence[str]:
 
 
 def get_app_module(app: str, name: str) -> Optional[ModuleType]:
-    """Get a named module of an app."""
+    """Get the settings module of an app."""
     pkg = ".".join(app.split(".")[:-2])
-
+    mod_settings = None
     while "." in pkg:
         try:
-            return import_module(f"{pkg}.{name}")
+            return import_module(f"{app}.{name}")
         except ImportError:
             # Import errors are non-fatal.
             pkg = ".".join(pkg.split(".")[:-1])
 
-    # The app does not have this module
+    # The app does not have settings
     return None