Reduce retries from 100 in 5 minutes to 5.

Summary:
This revision reduces the maximum number of retries in the 5 minutes span from
100 to 5 since we definitely cannot reach 100 retries in 5 minutes given the
current load we have.
This should prevent never-ending loops between the account monitors and the
folder engines, something we were observing in our EAS code.

Fix T670.

Test Plan: Non-disruptive change. Nothing bad should happen.

Reviewers: emfree, kav-ya

Reviewed By: kav-ya

Subscribers: spang

Maniphest Tasks: T670

Differential Revision: https://review.inboxapp.com/D925