bitbake: prserv: Adapt autostart to bitbake-worker

With the change to bitbake-worker we need to ensure the workers know
how to contact the PR service, the magic 0 port and singleton is
no longer enough.

(Bitbake rev: c761751e259bb8e940552a28794b45887b5a72d9)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

bitbake/bin/bitbake-worker

@@ -280,6 +280,7 @@ class BitbakeWorker(object):
         bb.msg.loggerDefaultVerbose = self.workerdata["logdefaultverbose"]
         bb.msg.loggerVerboseLogs = self.workerdata["logdefaultverboselogs"]
         bb.msg.loggerDefaultDomains = self.workerdata["logdefaultdomain"]
+        self.data.setVar("PRSERV_HOST", self.workerdata["prhost"])
 
     def handle_ping(self, _):
         workerlog_write("Handling ping\n")