Trigger initial DNS-SD publishing
Previously code relied on manager to do so, but call was lost somehow.
Safer to do it from here.

BUG:25463798
Change-Id: Ia00e666123524188e4772c67ce1cd250f0121dd0
Reviewed-on: https://weave-review.googlesource.com/1482
Reviewed-by: Alex Vakulenko <avakulenko@google.com>
diff --git a/src/privet/publisher.cc b/src/privet/publisher.cc
index 62e980e..55c9fe4 100644
--- a/src/privet/publisher.cc
+++ b/src/privet/publisher.cc
@@ -34,6 +34,7 @@
   CHECK(device_);
   CHECK(cloud_);
   CHECK(dns_sd_);
+  Update();
 }
 
 Publisher::~Publisher() {
@@ -73,7 +74,8 @@
   auto new_data = std::make_pair(port, txt_record);
   if (published_ == new_data)
     return;
-  VLOG(1) << "Updating DNS-SD";
+
+  VLOG(1) << "Updating service using DNS-SD, port: " << port;
   published_ = new_data;
   dns_sd_->PublishService(kPrivetServiceType, port, txt_record);
 }