(Bug 50121) Only return 404 when page does not exist

 * Distinguishes API request failures.

Change-Id: I609de747b80709fccdaf57df66ec5dafcf75ab08
Downgrade cache miss level to info

 * Too much noise in logstash.

Change-Id: I3d412244148adb538b1a5aa37da687ee331d297e