[Feature] Changes required for non public tenants (#370)

Co-authored-by: Tim Lorsbach <tim@lorsba.ch>
Reviewed-on: enviPath/enviPy#370

epdb/legacy_api.py

@@ -1969,7 +1969,7 @@ def add_pathway_edge(request, package_uuid, pathway_uuid, e: Form[CreateEdge]):
 
         return redirect(new_e.url)
     except ValueError:
-        return 403, {"message": "Adding node failed!"}
+        return 403, {"message": "Adding Edge failed!"}
 
 
 @router.delete("/package/{uuid:package_uuid}/pathway/{uuid:pathway_uuid}/edge/{uuid:edge_uuid}")