Bump up # of attempted samples per second (@alpert's advise is wise and should be heeded)

Test Plan: Loaded page, verified that mini profiler still loaded and showed sampling data.

Reviewers: alpert

Differential Revision: http://phabricator.khanacademy.org/D1028
Merge branch 'master' of https://github.com/kamens/gae_mini_profiler