BUG/MINOR: server: Don't warn fallback IP is used during init-addr resolution

When a fallback IP address is provided in the list of methods to use to
resolve the server address, a warning is emitted if previous methods
failed. The aim is to inform this address will be used for the
server. However, it is valid use-case. It is the expected behavior. There is
no reason to emit a warning. Having a message during HAProxy startup to
inform the fallback IP address will be used is probably a good idea. But it
should be a notice not a warning. Otherwise, checking the configuration
validity will always failed, just like starting HAProxy in zero-warning
mode while the option was set on purpose.

This patch should fix the issue #2627. It must be backported to all stable
versions.

(cherry picked from commit abaafda4850c64183bb69d6a62675b7405993f4a)
Signed-off-by: Willy Tarreau <w@1wt.eu>
(cherry picked from commit 1c15af0dc73a9507cbcef10ebad762d61a70da9b)
Signed-off-by: Willy Tarreau <w@1wt.eu>
(cherry picked from commit 476afe3c422a107e85b008633f21d6258b6e46eb)
Signed-off-by: Willy Tarreau <w@1wt.eu>
diff --git a/src/server.c b/src/server.c
index 25ecf53..9c7dc83 100644
--- a/src/server.c
+++ b/src/server.c
@@ -4142,8 +4142,8 @@
 		case SRV_IADDR_IP:
 			ipcpy(&srv->init_addr, &srv->addr);
 			if (return_code) {
-				ha_warning("could not resolve address '%s', falling back to configured address.\n",
-					   name);
+				ha_notice("could not resolve address '%s', falling back to configured address.\n",
+					  name);
 			}
 			goto out;