connect.c: Fixed compilation warning when no verbose string support

warning: unused parameter 'reason'

lib/connect.c

@@ -1333,8 +1333,13 @@ CURLcode Curl_socket(struct connectdata *conn,
 void Curl_conncontrol(struct connectdata *conn, bool closeit,
                       const char *reason)
 {
+#if defined(CURL_DISABLE_VERBOSE_STRINGS)
+  (void) reason;
+#endif
+
   infof(conn->data, "Marked for [%s]: %s\n", closeit?"closure":"keep alive",
         reason);
+
   conn->bits.close = closeit; /* the only place in the source code that should
                                  assign this bit */
 }