Add the logs dependency in ./configure

Author: Julow

configure

@@ -401,7 +401,8 @@ check_library lwt "See: http://ocsigen.org/lwt"
 check_library lwt.unix  "Missing support for 'unix' in lwt."
 check_library lwt_react   "See: http://ocsigen.org/lwt"
 check_library lwt_ssl   "See: http://ocsigen.org/lwt"
-check_library lwt_log   "See: http://ocsigen.org/lwt"
+check_library logs ""
+check_library logs-syslog "Missing syslog support."
 
 check_library re "See: https://github.com/ocaml/ocaml-re/"
 check_library cryptokit "See: http://pauillac.inria.fr/~xleroy/software.html#cryptokit"