Merge pull request #4142 from edx/youngstrom/github_fix

jenkins_common github template fix

playbooks/roles/jenkins_common/templates/config/github_config.yml.j2

@@ -4,5 +4,5 @@
   MANAGE_HOOKS: '{{ config.MANAGE_HOOKS }}'
   USE_CUSTOM_API_URL: '{{ config.USE_CUSTOM_API_URL }}'
   API_URL: '{{ config.API_URL }}'
-  CACHE_SIZE: '{{ config.CACHE_SIZE}}'
+  CACHE_SIZE: {{ config.CACHE_SIZE}}
 {% endfor %}