Fix dead link

[melap]

R: @kennknowles (as you have the context of the move)

[melap]

R: @lukecwik

[lukecwik]

@asfgit merge

[asfgit]

MergeBot: Merge: PR 333 in state error with description Unexpected Error: HTTPSConnectionPool(host='builds.apache.org', port=443): Max retries exceeded with url: /job/Mesos/api/python?tree=jobs%5Bname%2Ccolor%5D (Caused by NewConnectionError('<requests.packages.urllib3.connection.VerifiedHTTPSConnection object at 0x7f7ec5e87150>: Failed to establish a new connection: [Errno -5] No address associated with hostname',)).. URL: http://mergebot-vm.apache.org/beam-website/333.

[asfgit]

Error: MergeBot encountered an unexpected error while processing this PR: HTTPSConnectionPool(host='builds.apache.org', port=443): Max retries exceeded with url: /job/Mesos/api/python?tree=jobs%5Bname%2Ccolor%5D (Caused by NewConnectionError('<requests.packages.urllib3.connection.VerifiedHTTPSConnection object at 0x7f7ec5e87150>: Failed to establish a new connection: [Errno -5] No address associated with hostname',)).

[lukecwik]

@asfgit merge