disable spammy logging

Summary: This message is printed on every service startup, which makes it one of the top logs in our logview (over 1M per day). It doesn't seem to indicate any actual problem.

Reviewed By: zhangqunshu, vit-ka

Differential Revision: D54869983

fbshipit-source-id: 7b4bcf13a6a5c2e48dfa03a19e5d6dc6e7a3b8f6

mcrouter/ConfigApi.cpp

@@ -61,8 +61,8 @@ bool ensureConfigDirectoryExists(boost::filesystem::path directory) {
     LOG(WARNING) << "Failed to create directory '" << directory
                  << "': " << result.error().what();
   } else {
-    LOG_FIRST_N(WARNING, 10) << "Parent directory '" << directory.parent_path()
-                             << "' does not exist.";
+    VLOG(1) << "Parent directory '" << directory.parent_path()
+            << "' does not exist.";
   }
   return false;
 }