bump diego-datadog-templates
bump diego-datadog-templates

Submodule diego-datadog-templates 58f1e4b..c51b2df:
  > Fix the deployment tag on the benchmark timeboard

[#153928213]

Signed-off-by: Edwin Xie <6bc24e9c160281972837d9e13287696d26612564@pivotal.io>

pivotal-cf-experimental/datadog-config-oss,pivotal-cf-experimental/datadog-config-oss