Adding back 'hide empty chat rooms' setting, was disabled at some point during 6.0 dev but should be enabled back

app/src/main/assets/linphonerc_default

@@ -39,7 +39,7 @@ version_check_url_root=https://www.linphone.org/releases
 max_calls=10
 history_max_size=100
 conference_layout=1
-hide_empty_chat_rooms=0
+hide_empty_chat_rooms=1
 
 [fec]
 fec_enabled=1

app/src/main/java/org/linphone/core/CoreContext.kt

@@ -453,6 +453,9 @@ class CoreContext @UiThread constructor(val context: Context) : HandlerThread("C
                         "$TAG Setting default contacts list filter to [${corePreferences.contactsFilter}]"
                     )
                 }
+
+                // Add that flag back, was disabled for a time during dev process
+                core.config.setBool("misc", "hide_empty_chat_rooms", true)
             }
 
             corePreferences.linphoneConfigurationVersion = currentVersion