Extend maxconn for galera haproxy

Default "8000" hardcoded in formula and for large deployments
it is not enough. Raising this only for database proxies.

PROD-36509

Change-Id: I979c0a52b6d61dc08accd7d90ab3b1698d40286d
(cherry picked from commit c82e6c00611c10851b8491867bb7fc5d7ffea95c)
3 files changed