Log metric that produced exception
Log metric that produced exception

To help diagnose issues such as those reported in
graphite-project/graphite-web#282

Backport from 80d111f8a270c5272089c280366f44a36d905eb4 on master branch.

Talkdesk/graphite-web,Talkdesk/graphite-web,Talkdesk/graphite-web,Talkdesk/graphite-web,Talkdesk/graphite-web,Talkdesk/graphite-web