Merge the tip of origin/release/proposed/2019.2.0 into origin/release/2019.2.0

be5060d Refactor key-fetch
a7ae5c9 Add nginx state to master_config
2249f88 Fix wait for salt warm-up check
6090625 Add possibility not install updates

Change-Id: If77c648ed8ffa56c4f058c763e49ab01433f7248