test only with env variables set in conf.py

Signed-off-by: Victor Garcia Reolid <victor@seita.nl>

flexmeasures/utils/config_utils.py

@@ -82,7 +82,7 @@ def read_config(app: Flask, custom_path_to_config: str | None):
     path_to_config_instance = os.path.join(app.instance_path, "flexmeasures.cfg")
 
     # Custom config: not when testing (that should run completely on defaults) and documentation
-    if not app.testing and app.env != "documentation":
+    if not app.testing:
         used_path_to_config = read_custom_config(
             app, custom_path_to_config, path_to_config_home, path_to_config_instance
         )