memory leak fixes

lib/utils/place-outdial.js

@@ -215,6 +215,7 @@ class SingleDialer extends Emitter {
       if (this.confirmHook) this._executeApp(this.confirmHook);
       else this.emit('accept');
     } catch (err) {
+      this.inviteInProgress = null;
       const status = {callStatus: CallStatus.Failed};
       if (err instanceof SipError) {
         status.sipStatus = err.status;