Adjust Jenkinsfile for move of releng.aggregator to github

Change-Id: I7c5a0b70fda66207784e20c0f118f4b4ecf10e29
Reviewed-on: https://git.eclipse.org/r/c/platform/eclipse.platform.releng/+/190629
Tested-by: Platform Bot <platform-bot@eclipse.org>
Reviewed-by: Alexander Kurtakov <akurtako@redhat.com>
diff --git a/Jenkinsfile b/Jenkinsfile
index 55b1485..26e6daf 100644
--- a/Jenkinsfile
+++ b/Jenkinsfile
@@ -44,7 +44,7 @@
 		}
 		stage('Check freeze period') {
 			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'