How to add branch-2.7 to Jenkins white list

[Wangda Tan]

Hi Hadoop-dev,

Now we are working on branch-2.7 for 2.7.1 release but I found branch-2.7
may not be added to Jenkins white list. For example: YARN-3434 cannot
trigger Jenkins build.

Could anybody help to add it?

Thanks,
Wangda