Run the History persister only on the leading server.

(02:59:39 PM) wsorenson_hs_: i think some of the managed stuff needs to only run on the master
(02:59:54 PM) wsorenson_hs_: for instance the history persister

this changes the persister to only run on the leading master.
Merge pull request #365 from hgschmie/run-persister-only-on-master

Run the History persister only on the leading server.