default play name to hosts entry

return to previous behaviour as now the name was left blank

lib/ansible/playbook/play.py

@@ -105,6 +105,8 @@ class Play(Base, Taggable, Become):
 
     @staticmethod
     def load(data, variable_manager=None, loader=None):
+        if ('name' not in data or data['name'] is None) and 'hosts' in data:
+            data['name'] = data['hosts']
         p = Play()
         return p.load_data(data, variable_manager=variable_manager, loader=loader)