Allow auto-loading of plugins in certain conditions (#3762)

Ref: https://github.com/matmair/InvenTree/commit/52af1966941ce564bae485988c40b8161d6f201e

InvenTree/plugin/apps.py

@@ -27,7 +27,7 @@ class PluginAppConfig(AppConfig):
     def ready(self):
         """The ready method is extended to initialize plugins."""
         if settings.PLUGINS_ENABLED:
-            if not canAppAccessDatabase(allow_test=True):
+            if not canAppAccessDatabase(allow_test=True, allow_plugins=True):
                 logger.info("Skipping plugin loading sequence")  # pragma: no cover
             else:
                 logger.info('Loading InvenTree plugins')