[MINOR] use nolinger on health-checks if backend is set to nolinger

If the administrator finds it useful to disable lingering on the backend,
let's disable lingering on health-checks too.
diff --git a/src/checks.c b/src/checks.c
index 490ff02..0cd1a87 100644
--- a/src/checks.c
+++ b/src/checks.c
@@ -316,6 +316,10 @@
 			    (setsockopt(fd, IPPROTO_TCP, TCP_NODELAY, (char *) &one, sizeof(one)) != -1)) {
 				//fprintf(stderr, "process_chk: 3\n");
 
+				if (s->proxy->options & PR_O_TCP_NOLING) {
+					/* We don't want to useless data */
+					setsockopt(fd, SOL_SOCKET, SO_LINGER, (struct linger *) &nolinger, sizeof(struct linger));
+				}
 				
 				if (s->check_addr.sin_addr.s_addr)
 					/* we'll connect to the check addr specified on the server */