### Description Similar to pua:default_expires, a default expire value could be added for subscriptions. The default expiration values are now hard coded for presence modules, in presence_*/add_events.c files.

### Expected behavior Default expiration value that is configurable.

#### Actual observed behavior Default expiration value is 3600.

### Possible Solutions Adding a parameter presence : default_expires and use it in all presence_*/add_events.c files. I can implement this myself.