Add host to gulpfile (prebid#5710)

* Add host to gulpfile

* Edit arg.host to FAKE_SERVER_HOST

Co-authored-by: VasekProchazka <[email protected]>

Author: 2 people

gulpfile.js

@@ -110,6 +110,7 @@ function watch(done) {
   connect.server({
     https: argv.https,
     port: port,
+    host: FAKE_SERVER_HOST,
     root: './',
     livereload: true
   });