Update ghprb plugin config, disable automatic management of webhooks.

Change-Id: Ie4c10a4278f5a66609ab0eeb23522355d1a52648
diff --git a/jenkins/config/org.jenkinsci.plugins.ghprb.GhprbTrigger.xml b/jenkins/config/org.jenkinsci.plugins.ghprb.GhprbTrigger.xml
index f6a573a..4bfd091 100644
--- a/jenkins/config/org.jenkinsci.plugins.ghprb.GhprbTrigger.xml
+++ b/jenkins/config/org.jenkinsci.plugins.ghprb.GhprbTrigger.xml
@@ -1,13 +1,15 @@
 <?xml version='1.0' encoding='UTF-8'?>
-<org.jenkinsci.plugins.ghprb.GhprbTrigger_-DescriptorImpl>
+<org.jenkinsci.plugins.ghprb.GhprbTrigger_-DescriptorImpl plugin="ghprb@1.39.0">
   <configVersion>1</configVersion>
   <whitelistPhrase>.*add\W+to\W+whitelist.*</whitelistPhrase>
   <okToTestPhrase>.*ok\W+to\W+test.*</okToTestPhrase>
   <retestPhrase>.*test\W+this\W+please.*</retestPhrase>
   <skipBuildPhrase>.*\[skip\W+ci\].*</skipBuildPhrase>
+  <blackListCommitAuthor></blackListCommitAuthor>
   <cron>H/5 * * * *</cron>
   <useComments>false</useComments>
   <useDetailedComments>false</useDetailedComments>
+  <manageWebhooks>false</manageWebhooks>
   <unstableAs>FAILURE</unstableAs>
   <autoCloseFailedPullRequests>false</autoCloseFailedPullRequests>
   <displayBuildErrorsOnDownstreamBuilds>false</displayBuildErrorsOnDownstreamBuilds>
@@ -22,7 +24,6 @@
   </githubAuth>
   <adminlist></adminlist>
   <requestForTestingPhrase>Can one of the admins verify this patch?</requestForTestingPhrase>
-  <jobs/>
   <extensions>
     <org.jenkinsci.plugins.ghprb.extensions.status.GhprbSimpleStatus>
       <commitStatusContext>ci.bazel.build</commitStatusContext>