xadhoom created an issue (kamailio/kamailio#4252)
### Description
A kamailio cluster which replicates presentities and usrloc via dmq may incur into duplicated presentities and notifications depending on config.
The problematic setup, where each kamailio node has the following setup: - presence enabled with dmq - usrloc distributed with dmq - pua_reginfo used to publish reginfo to self
Really is multiplicated by the numbers of nodes, so 4 nodes -> 4 times notifications and presentities.
### Troubleshooting The problem arise because pua_reginfo hooks to usrloc and every time a "save()" is done a publish is sent, which is by design. Then the handled publish generates a presentity which is replicated via dmq from presence module.
Now, if also usrloc is replicated via DMQ, the handling of such message still trigger the hook, causing another publish with generates a different presentiy, since is new and the e-tag is different.
This causes subscribers to receive <number of nodes> notifications on every status change.
### Possible Solutions
The approach can be to optionally disable that hook (basically making pua_reginfo skipping publish) when handling a message via DMQ, so the usrloc replica is just saved.
In other modules, like pua_dialoginfo or pua_usrloc this can be already done, since publishing can be controlled from script.
### Additional Information
* **Kamailio Version**
``` 6.0.1 ```