MT#62181 fix thread::join usage

These methods are called from the thread context itself. A thread cannot
join itself.

Change-Id: Id074f713e36693d65b0d07ef8d3b902769df99fc

apps/db_reg_agent/DBRegAgent.cpp

@@ -820,6 +820,7 @@ void DBRegAgent::process(AmEvent* ev) {
     if(sys_ev){	
       DBG("Session received system Event\n");
       if (sys_ev->sys_event == AmSystemEvent::ServerShutdown) {
+	stop();
 	registration_scheduler.stop();
 	registration_scheduler.join();
       }
@@ -1794,7 +1795,6 @@ void DBRegAgentProcessorThread::process(AmEvent* ev) {
       if (sys_ev->sys_event == AmSystemEvent::ServerShutdown) {
 	DBG("stopping processor thread\n");
 	stop();
-	join();
       }
       return;
     }

apps/xmlrpc2di/XMLRPC2DI.cpp

@@ -489,7 +489,6 @@ void XMLRPC2DIServer::process(AmEvent* ev) {
 	DBG("XMLRPC2DIServer received system Event: ServerShutdown, "
 	    "stopping thread\n");
 	stop();
-	join();
       }
       return;
     }