Terminate all tcpsrv threads properly

Graceful shutdown of Rsyslog could lead to segmentation faults when
multiple imtcp inputs are being used. That is because the rest of the
tcpsrv threads are left behind running, while their underlying objects
are being disposed by the main thread as part of the module
de-initialization.

Signed-off-by: Gabor Orosz <goro@goro.io>

plugins/imtcp/imtcp.c

@@ -1007,6 +1007,7 @@ CODESTARTrunInput
 	iRet = tcpsrv.Run(tcpsrv_root->tcpsrv);
 
 	/* de-init remaining servers */
+	etry = tcpsrv_root->next;
 	while(etry != NULL) {
 		stopSrvWrkr(etry);
 		etry = etry->next;