set-parent-project: evict child projects from project cache

When a project gets reparented it's not evicted from the project cache
and the cached project instance still points to the old parent
project.

Due to this e.g. the 'ls-projects --tree' command delivers incorrect
results right after a project was reparented with the
'set-project-parent' command.

Change-Id: If64f46688a2a03ffed6bb67ca8161bb16e9bb59a
Signed-off-by: Edwin Kempin <edwin.kempin@sap.com>

gerrit-sshd/src/main/java/com/google/gerrit/sshd/commands/AdminSetParent.java

@@ -132,6 +132,8 @@ final class AdminSetParent extends BaseCommand {
       } catch (ConfigInvalidException e) {
         throw new Failure(1, "Cannot update project " + name, e);
       }
+
+      projectCache.evict(pc.getProject());
     }
 
     if (err.length() > 0) {