bump locket
bump locket

[finishes #144635439]

Submodule src/code.cloudfoundry.org/locket be082beb..7ff04658:
  > regenerate protobuf files

cloudfoundry-incubator/diego-release,cloudfoundry-incubator/diego-release,cloudfoundry-incubator/diego-release,cloudfoundry-incubator/diego-release