add support for fromHost in createCall rest api

lib/http-routes/api/create-call.js

@@ -41,7 +41,8 @@ router.post('/', async(req, res) => {
       'X-Jambonz-Routing': target.type,
       'X-Jambonz-FS-UUID': srf.locals.fsUUID,
       'X-Call-Sid': callSid,
-      'X-Account-Sid': accountSid
+      'X-Account-Sid': accountSid,
+      ...(restDial.fromHost && {'X-Preferred-From-Host': this.from.host})
     };
 
     switch (target.type) {

lib/tasks/rest_dial.js

@@ -11,6 +11,7 @@ class TaskRestDial extends Task {
     super(logger, opts);
 
     this.from = this.data.from;
+    this.fromHost = this.data.fromHost;
     this.to = this.data.to;
     this.call_hook = this.data.call_hook;
     this.timeout = this.data.timeout || 60;

lib/tasks/specs.json

@@ -341,6 +341,7 @@
       "call_hook": "object|string",
       "call_status_hook": "object|string",
       "from": "string",
+      "fromHost": "string",
       "speech_synthesis_vendor": "string",
       "speech_synthesis_voice": "string",
       "speech_synthesis_language": "string",