bump silk
bump silk

[#145244693]

Submodule src/code.cloudfoundry.org/silk 5df22d6..326a1ea:
  > [cni] Latency and buffer size is kernel agnostic
  > [cni] Use container IP from store for IFB delete
  > [cni] DEL no longer depends on the silk-daemon
  > [cni] Skip running bandwidth tests if ifb device not available

Signed-off-by: Joachim Valdez <f4115f6bcd6858c277581a1d9da83b9914dce2c3@us.ibm.com>

cloudfoundry-incubator/cf-networking-release,cloudfoundry-incubator/cf-networking-release,cloudfoundry-incubator/cf-networking-release,cloudfoundry-incubator/cf-networking-release