REORG: server: Export srv_settings_cpy() function

This function will be used to init a proxy with settings of the default
proxy. It is mandatory to fix a bug. To do so, it must be exposed.
diff --git a/src/server.c b/src/server.c
index 73a7323..debbd71 100644
--- a/src/server.c
+++ b/src/server.c
@@ -2169,7 +2169,7 @@
  * <srv_tmpl> distinguishes these two cases (must be 1 if <srv> is a template,
  * 0 if not).
  */
-static void srv_settings_cpy(struct server *srv, const struct server *src, int srv_tmpl)
+void srv_settings_cpy(struct server *srv, const struct server *src, int srv_tmpl)
 {
 	/* Connection source settings copy */
 	srv_conn_src_cpy(srv, src);