Handle unknown signal messages from the server (#568)

When we switched to using oneof in generated protobufs, it broke the ability to handle unknown signal messages from the server. This is due to the protobuf parser returning undefined for message field, versus a new value for $case.

.changeset/honest-bikes-know.md

@@ -0,0 +1,5 @@
+---
+'livekit-client': patch
+---
+
+Fixed handling of unknown signal messages

src/api/SignalClient.ts

@@ -493,7 +493,11 @@ export class SignalClient {
   }
 
   private handleSignalResponse(res: SignalResponse) {
-    const msg = res.message!;
+    const msg = res.message;
+    if (msg == undefined) {
+      log.debug('received unsupported message');
+      return;
+    }
     if (msg.$case === 'answer') {
       const sd = fromProtoSessionDescription(msg.answer);
       if (this.onAnswer) {

src/room/RTCEngine.ts

@@ -681,14 +681,14 @@ export default class RTCEngine extends (EventEmitter as new () => TypedEventEmit
       return;
     }
 
-    log.debug(`${connection} disconnected`);
+    log.warn(`${connection} disconnected`);
     if (this.reconnectAttempts === 0) {
       // only reset start time on the first try
       this.reconnectStart = Date.now();
     }
 
     const disconnect = (duration: number) => {
-      log.info(
+      log.warn(
         `could not recover connection after ${this.reconnectAttempts} attempts, ${duration}ms. giving up`,
       );
       this.emit(EngineEvent.Disconnected);