Gerrit functions extracted into own file

Change-Id: I8589be350238b5886dd44d060266c2c599c9386b
diff --git a/src/com/mirantis/mk/Git.groovy b/src/com/mirantis/mk/Git.groovy
index bfd00e5..55218cc 100644
--- a/src/com/mirantis/mk/Git.groovy
+++ b/src/com/mirantis/mk/Git.groovy
@@ -128,7 +128,7 @@
     ssl.prepareSshAgentKey(credentialsId)
     ssl.ensureKnownHosts(targetUrl)
 
-    sh "git remote | grep target || git remote add target ${TARGET_URL}"
+    sh "git remote | grep target || git remote add target ${targetUrl}"
     agentSh "git remote update --prune"
     for (i=0; i < branches.size; i++) {
         branch = branches[i]