CLEANUP: connections: align function declaration

srv_cleanup_connections() is supposed to be static, so mark it as so.
This patch should be backported where commit 6318d33ce625
("BUG/MEDIUM: connections: force connections cleanup on server changes")
will be backported, that is to say v1.9 to v2.1.

Fixes: 6318d33ce625 ("BUG/MEDIUM: connections: force connections cleanup
on server changes")
Signed-off-by: William Dauchy <w.dauchy@criteo.com>
(cherry picked from commit 707ad328ef6f9061f2da04f81431bc2fe2b2348a)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>
(cherry picked from commit 7eab37b6819af685c647cf5a581e29fca2f3e079)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>
diff --git a/src/server.c b/src/server.c
index 9287502..580baf8 100644
--- a/src/server.c
+++ b/src/server.c
@@ -5347,7 +5347,7 @@
 /* cleanup connections for a given server
  * might be useful when going on forced maintenance or live changing ip/port
  */
-void srv_cleanup_connections(struct server *srv)
+static void srv_cleanup_connections(struct server *srv)
 {
 	struct connection *conn;
 	int did_remove;