Fix handle_create of ResourceGroup

When doing a non-batched create we call create_with_template(),
where we pass `self.stack.timeout_secs()` as `timeout_mins` which
increases the timeout by 60 times.

Change-Id: I225ece0d8e4b6cb4eba2d3a748bd3ce5cda4f5c9
Closes-Bug: #1705009
(cherry picked from commit 1591aca)

heat/engine/resources/openstack/heat/resource_group.py

@@ -364,8 +364,7 @@ def handle_create(self):
         else:
             names = self._resource_names()
             self.create_with_template(self._assemble_nested(names),
-                                      self.child_params(),
-                                      self.stack.timeout_secs())
+                                      self.child_params())
 
     def check_create_complete(self, checkers=None):
         if checkers is None: