Disable automatic registration of pull request hooks.
Disable automatic registration of pull request hooks.

We already set the hook in our bazelbuild organization settings.

Change-Id: I3b210872f69a84b89a665ca2aeeab3a6cdb2145a

bazelbuild/continuous-integration,bazelbuild/continuous-integration,bazelbuild/continuous-integration,bazelbuild/continuous-integration,bazelbuild/continuous-integration,bazelbuild/continuous-integration,bazelbuild/continuous-integration,bazelbuild/continuous-integration