Adjust Jenkinsfile for move of releng.aggregator to github

Change-Id: I69ac70dd0e64db363fb70962f8aad97ca0c666a8
Reviewed-on: https://git.eclipse.org/r/c/platform/eclipse.platform.ui.tools/+/190630
Tested-by: Platform Bot <platform-bot@eclipse.org>
Reviewed-by: Alexander Kurtakov <akurtako@redhat.com>
diff --git a/Jenkinsfile b/Jenkinsfile
index 58362a6..fe86e95 100644
--- a/Jenkinsfile
+++ b/Jenkinsfile
@@ -48,7 +48,7 @@
 				}
 			}
 			steps {
-				sh "wget https://git.eclipse.org/c/platform/eclipse.platform.releng.aggregator.git/plain/scripts/verifyFreezePeriod.sh"
+				sh "wget https://raw.githubusercontent.com/eclipse-platform/eclipse.platform.releng.aggregator/master/scripts/verifyFreezePeriod.sh"
 				sh "chmod +x verifyFreezePeriod.sh"
 				withCredentials([string(credentialsId: 'google-api-key', variable: 'GOOGLE_API_KEY')]) {
 					sh './verifyFreezePeriod.sh'