[MERGE][#139202] Better message when a repository is locked

[Ian Clatworthy]

Ian Clatworthy has voted approve.
Status is now: Semi-approved


For details, see: 
http://bundlebuggy.aaronbentley.com/request/%3C2422be180805201918p5baf7b5fq1c10ea8b300adfbe%40mail.gmail.com%3E