fix(audio): always send unhold

Alway send the unhold command since it doesn't change flip the state
(contrary to the uuid_hold toggle command).

It's not idempotent, though - so always update the internal hold state
to prevent state mismatches preventing channels from being unheld.

akka-bbb-apps/src/main/scala/org/bigbluebutton/core/apps/voice/ListenOnlyModeToggledInSfuEvtMsgHdlr.scala

@@ -25,14 +25,15 @@ trait ListenOnlyModeToggledInSfuEvtMsgHdlr {
       // opposite of what we want.
       // The unhold (uuid_hold off) command is not affected by this, but we don't
       // want to send it if the channel is already unheld.
-      if (msg.body.enabled != vu.hold) {
+      if ((msg.body.enabled && !vu.hold) || !msg.body.enabled) {
         VoiceApp.holdChannelInVoiceConf(
           liveMeeting,
           outGW,
           vu.uuid,
           msg.body.enabled
         )
-      } else {
+      }
+
       // If the channel is already in the desired state, just make sure
       // any pending mute or unmute commands are sent.
       VoiceApp.handleChannelHoldChanged(
@@ -44,5 +45,4 @@ trait ListenOnlyModeToggledInSfuEvtMsgHdlr {
       )
     }
   }
-  }
 }