Fixed an error

Author: mesonepigreco

Modules/Relax.py

@@ -304,7 +304,7 @@ def relax(self, restart_from_ens = False, get_stress = False,
             if not os.path.exists(ensemble_loc):
                 os.makedirs(ensemble_loc)
             else:
-                if not os.isdir(ensemble_loc):
+                if not os.path.isdir(ensemble_loc):
                     ERR_MSG = """
 Error, the specified location to save the ensemble:
        '{}'