Fix a build error

src/local.c

@@ -1044,9 +1044,11 @@ int main(int argc, char **argv)
         case 'a':
             user = optarg;
             break;
+#ifdef HAVE_SETRLIMIT
         case 'n':
             nofile = atoi(optarg);
             break;
+#endif
         case 'u':
             mode = TCP_AND_UDP;
             break;

src/redir.c

@@ -675,9 +675,11 @@ int main(int argc, char **argv)
         case 'a':
             user = optarg;
             break;
+#ifdef HAVE_SETRLIMIT
         case 'n':
             nofile = atoi(optarg);
             break;
+#endif
         case 'u':
             mode = TCP_AND_UDP;
             break;

src/server.c

@@ -1346,9 +1346,11 @@ int main(int argc, char **argv)
         case 'a':
             user = optarg;
             break;
+#ifdef HAVE_SETRLIMIT
         case 'n':
             nofile = atoi(optarg);
             break;
+#endif
         case 'u':
             mode = TCP_AND_UDP;
             break;

src/tunnel.c

@@ -747,9 +747,11 @@ int main(int argc, char **argv)
         case 'a':
             user = optarg;
             break;
+#ifdef HAVE_SETRLIMIT
         case 'n':
             nofile = atoi(optarg);
             break;
+#endif
         case 'v':
             verbose = 1;
             break;

src/utils.c

@@ -233,7 +233,7 @@ void usage()
         "       [-c <config_file>]         The path to config file.\n");
 #ifdef HAVE_SETRLIMIT
     printf(
-        "       [-n <number>]              Max number of open files, only available on Linux.\n");
+        "       [-n <number>]              Max number of open files.\n");
 #endif
 #ifndef MODULE_REDIR
     printf(