Check the proxy inactive mysql port is ready before tests
Check the proxy inactive mysql port is ready before tests

This squashes a long-running flake caused the tests not waiting for the
inactive mysql port to be declared healthy and active by switchboard.

[#164882671]

Signed-off-by: Chris Tarazi <52172d1cc353fd06218578cc1e854d12546b9ed2@pivotal.io>

cloudfoundry-incubator/switchboard,cloudfoundry-incubator/switchboard,cloudfoundry-incubator/switchboard,cloudfoundry-incubator/switchboard