README: mention increase of MySQL connections
README: mention increase of MySQL connections

AlCutter/trillian,daviddrysdale/trillian,daviddrysdale/trillian,gdbelvin/trillian,RJPercival/trillian,RJPercival/trillian,gdbelvin/trillian,Martin2112/trillian,AlCutter/trillian,daviddrysdale/trillian,Martin2112/trillian,google/trillian,gdbelvin/trillian,Martin2112/trillian,google/trillian