CLEANUP: backend: Don't export connect_server anymore

connect_server() function is only called from backend.c. So make it static.
diff --git a/include/haproxy/backend.h b/include/haproxy/backend.h
index a6ac621..308848b 100644
--- a/include/haproxy/backend.h
+++ b/include/haproxy/backend.h
@@ -32,7 +32,6 @@
 int assign_server(struct stream *s);
 int assign_server_address(struct stream *s);
 int assign_server_and_queue(struct stream *s);
-int connect_server(struct stream *s);
 int srv_redispatch_connect(struct stream *t);
 void back_try_conn_req(struct stream *s);
 void back_handle_st_req(struct stream *s);
diff --git a/src/backend.c b/src/backend.c
index 0fed42a..83c4d52 100644
--- a/src/backend.c
+++ b/src/backend.c
@@ -1247,7 +1247,7 @@
  * The server-facing stream interface is expected to hold a pre-allocated connection
  * in s->csb->si->conn.
  */
-int connect_server(struct stream *s)
+static int connect_server(struct stream *s)
 {
 	struct connection *cli_conn = objt_conn(strm_orig(s));
 	struct connection *srv_conn = NULL;