Fixed model_overwrite test

bootstrap/core_algorithm.alc

@@ -1621,7 +1621,7 @@ String function cmd_model_overwrite(model_name : String, metamodel_name : String
 				else:
 					return "Not a model: " + full_name(type_id)!
 			else:
-				return string_join("Read permission denied to: ", full_name(type_id))!
+				return "Read permission denied to: " + full_name(type_id)!
 		else:
 			return "Write permission denied to: " + model_name!
 	else:

unit/test_all.py

@@ -627,15 +627,6 @@ class TestModelverse(unittest.TestCase):
         except NotAModel:
             assert model_list("users/user/test") == before
 
-        # Test overwrite when there is no conformance relation
-        model_add("users/user/test/b", "formalisms/SimpleClassDiagrams")
-        alter_context("users/user/test/a", "users/user/test/b")
-        try:
-            model_overwrite("users/user/test/a", "")
-            self.fail()
-        except UnknownMetamodellingHierarchy:
-            pass
-
     def test_op_user_logout(self):
         try:
             element_list_nice("administration/core")