fix inband dtmf does not work in dial verb (#1018)

lib/utils/place-outdial.js

@@ -349,6 +349,15 @@ class SingleDialer extends Emitter {
     if (Object.keys(opts).length > 0) {
       this.ep.set(opts);
     }
+    if (this.dialTask?.inbandDtmfEnabled && !this.ep.inbandDtmfEnabled) {
+      // https://developer.signalwire.com/freeswitch/FreeSWITCH-Explained/Modules/mod-dptools/6587132/#0-about
+      try {
+        this.ep.execute('start_dtmf');
+        this.ep.inbandDtmfEnabled = true;
+      } catch (err) {
+        this.logger.info(err, 'place-outdial:_configMsEndpoint - error enable inband DTMF');
+      }
+    }
   }
 
   /**