Move trash folders deletion in background

Deleting trash folders can take some time so execute in a separate
thread to not slow down Gerrit start up.

Change-Id: I07daa18ebcad41538186f97550a7f85faa074b4d
1 file changed
tree: 4ea286819fc62ec6543473371fa1f028ea6a7351
  1. .gitignore
  2. BUCK
  3. pom.xml
  4. src/