Remove mentions of multihost support from agent to server

Due to an issue with the implementation,
we do not wish to document this as an official feature of
PEM 9.7.0 at this time

Author: sonotley

product_docs/docs/pem/9/pem_rel_notes/970_rel_notes.mdx

@@ -12,7 +12,6 @@ New features, enhancements, bug fixes, and other changes in PEM 9.7.0 include:
 | Enhancement  | Added PGD extension details in the Core usage report.                                                                                                                                       |
 | Enhancement  | If max_connections is set to 1 in the `agent.cfg` file, PEM agent startup process makes it to 2 in the backend code to avoid PEM's probe data collection failure. [Support ticket: #101924] |
 | Enhancement  | Probes are now re-run on restart of agent and monitored server.                                                                                                                             |
-| Enhancement  | Added support for multi-host connection strings for the connections from agent to PEM Server.                                                                                               |
 | Enhancement  | Introduced v12 REST API to fix the API schema for alerts (GET) and alert templates (GET/PUT/POST).                                                                                          |
 | Bug fix | Fixed an issue where the version information was missing in the `pemworker` utility usage.                                                                                                  |
 | Bug fix | Fixed an issue with `reminder_notification_interval` setting. Now you can configure this parameter to a value less than 1 hour.                                                             |

product_docs/docs/pem/9/registering_agent.mdx

@@ -108,24 +108,6 @@ When invoking the pemworker utility, append command line options to the command
 ## Advanced usage
 The following are some advanced options for PEM agent registration.
 
-### Registering multiple hosts for high availability
-
-If you are using PEM to manage multiple database servers for high availability, register your PEM agent with the primary, as well as any standby hosts. In a switchover scenario, registering all hosts allows the PEM agent to automatically recognize the new primary instance (that used to be a standby) without any manual intervention.
-
-If you don't register all hosts, the PEM agent won't be able to perform write queries on the new primary host until it is manually registered. 
-
-Use the `--pem-server` and `--pem-port` options to specify all hosts when registering the PEM agent: 
-
-```
-/usr/edb/pem/agent/bin/pemworker --register-agent \ --pem-server host1,host2 \ --pem-port 5444,5432
-``` 
-
-!!!note 
-   After configuring all hosts, the PEM agent tries to connect to a host in the specified order. However, it will only be able to connect to the host currently accepting connections, the primary host.
-!!! 
-
-See [Specifying Multiple Hosts](https://www.postgresql.org/docs/current/libpq-connect.html#LIBPQ-MULTIPLE-HOSTS) for more information. 
-
 ### Setting the agent ID
 Each registered PEM agent must have a unique agent ID. The value `max(id)+1` is assigned to each agent ID unless a value is provided using the `-o` options as shown [below](#overriding-default-configurations---examples).