jenkins: handle IPv4 remote address converted to IPv6 (#161)

After the Jenkins IP whitelist was activated, the inline PR status
reports for nodejs/node seems to be broken.

Seems like the issue here is that IPv4 remote addresses are converted
to IPv6, which wasn't expected too happen.. Stripping any IPv6 parts
off the remote addresses should make our IPv4 comparisons work as
expected.

Refs nodejs/build#1016
Refs nodejs/build#985

Author: phillipj

scripts/jenkins-status.js

@@ -6,7 +6,7 @@ const enabledRepos = ['citgm', 'http-parser', 'node']
 const jenkinsIpWhitelist = process.env.JENKINS_WORKER_IPS ? process.env.JENKINS_WORKER_IPS.split(',') : []
 
 function isJenkinsIpWhitelisted (req) {
-  const ip = req.connection.remoteAddress
+  const ip = req.connection.remoteAddress.split(':').pop()
 
   if (jenkinsIpWhitelist.length && !jenkinsIpWhitelist.includes(ip)) {
     req.log.warn({ ip }, 'Ignoring, not allowed to push Jenkins updates')