cleanup custom version command

Jenkinsfile

@@ -103,7 +103,8 @@ pipeline {
       steps{
         script{
           env.EXT_RELEASE = sh(
-            script: ''' curl -s https://golang.org/dl/ | awk -F '(go|.linux-amd64.tar.gz)' '/linux-amd64.tar.gz/ {print $4;exit}' ''',
+            script: ''' curl -s https://golang.org/dl/ | awk -F '(go|.linux-amd64.tar.gz)' '/linux-amd64.tar.gz/ {print $2;exit}'
+ ''',
             returnStdout: true).trim()
             env.RELEASE_LINK = 'custom_command'
         }

jenkins-vars.yml

@@ -3,7 +3,8 @@
 # jenkins variables
 project_name: docker-cloud9
 external_type: na
-custom_version_command: "curl -s https://golang.org/dl/ | awk -F '(go|.linux-amd64.tar.gz)' '/linux-amd64.tar.gz/ {print $2;exit}'"
+custom_version_command: |
+  curl -s https://golang.org/dl/ | awk -F '(go|.linux-amd64.tar.gz)' '/linux-amd64.tar.gz/ {print $2;exit}'
 release_type: prerelease
 release_tag: go
 ls_branch: go