got error when our pull request builder plugin trying to connect to github.
Feb 23, 2018 4:08:00 PM SEVERE org.jenkinsci.plugins.ghprb.GhprbGitHubAuth buildConnection
Unable to connect using credentials: ________________________________
org.kohsuke.github.HttpException: Server returned HTTP response code: -1, message: 'null' for URL: https://api.github.com/user
at org.kohsuke.github.Requester.parse(Requester.java:633)
at org.kohsuke.github.Requester.parse(Requester.java:594)
at org.kohsuke.github.Requester._to(Requester.java:272)
at org.kohsuke.github.Requester.to(Requester.java:234)
at org.kohsuke.github.GitHub.getMyself(GitHub.java:384)
at org.kohsuke.github.GitHub.(GitHub.java:158)
at org.kohsuke.github.GitHubBuilder.build(GitHubBuilder.java:207)
at org.jenkinsci.plugins.ghprb.GhprbGitHubAuth.buildConnection(GhprbGitHubAuth.java:195)
at org.jenkinsci.plugins.ghprb.GhprbGitHubAuth.getConnection(GhprbGitHubAuth.java:204)
at org.jenkinsci.plugins.ghprb.GhprbTrigger.getGitHub(GhprbTrigger.java:431)
at org.jenkinsci.plugins.ghprb.GhprbRepository.initGhRepository(GhprbRepository.java:86)
at org.jenkinsci.plugins.ghprb.GhprbRepository.check(GhprbRepository.java:130)
at org.jenkinsci.plugins.ghprb.GhprbTrigger.run(GhprbTrigger.java:300)
at hudson.triggers.Trigger.checkTriggers(Trigger.java:272)
at hudson.triggers.Trigger$Cron.doRun(Trigger.java:221)
at hudson.triggers.SafeTimerTask.run(SafeTimerTask.java:50)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:304)
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.access$301(ScheduledThreadPoolExecutor.java:178)
at java.util.concurrent.ScheduledThreadPoolExecutor$ScheduledFutureTask.run(ScheduledThreadPoolExecutor.java:293)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:745)
Caused by: javax.net.ssl.SSLException: Received fatal alert: protocol_version
at sun.security.ssl.Alerts.getSSLException(Alerts.java:208)
at sun.security.ssl.Alerts.getSSLException(Alerts.java:154)
at sun.security.ssl.SSLSocketImpl.recvAlert(SSLSocketImpl.java:1979)
at sun.security.ssl.SSLSocketImpl.readRecord(SSLSocketImpl.java:1086)
at sun.security.ssl.SSLSocketImpl.performInitialHandshake(SSLSocketImpl.java:1332)
at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1359)
at sun.security.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1343)
at sun.net.www.protocol.https.HttpsClient.afterConnect(HttpsClient.java:563)
at sun.net.www.protocol.https.AbstractDelegateHttpsURLConnection.connect(AbstractDelegateHttpsURLConnection.java:185)
at sun.net.www.protocol.http.HttpURLConnection.getInputStream(HttpURLConnection.java:1301)
at java.net.HttpURLConnection.getResponseCode(HttpURLConnection.java:468)
at sun.net.www.protocol.https.HttpsURLConnectionImpl.getResponseCode(HttpsURLConnectionImpl.java:338)
at org.kohsuke.github.Requester.parse(Requester.java:602)
... 22 more