prevent crash when single-message history contains bot command

src/client.ts

@@ -148,7 +148,7 @@ export default abstract class CollabVMClient {
       message.length === 3 &&
       !IsSystemChatInstruction(message)
     ) {
-      if (message[1] != this._username) {
+      if (message[1] != this._username && this._users.some(u => u.GetName() === message[1])) {
         this.OnChat(message[1], message[2]);
         return;
       }