Remove leftover call to _create_stestrepository

This method doesn't exist and causes runs to fail.

Change-Id: I639477e3702029e86509bdf5ae2826e2069a4288
diff --git a/tempest/cmd/run.py b/tempest/cmd/run.py
index 986602b..bd94fa9 100644
--- a/tempest/cmd/run.py
+++ b/tempest/cmd/run.py
@@ -161,7 +161,6 @@
         # local execution with config file mode
         elif parsed_args.config_file:
             self._create_stestr_conf()
-            self._create_stestrepository()
         elif not os.path.isfile('.stestr.conf'):
             print("No .stestr.conf file was found for local execution")
             sys.exit(2)