Remove unnecessary 'unsign' parameter to maven_jar

Update bazlets to the latest stable-3.0 revision which removes
the 'unsign' parameter from maven_jar, and remove it from the
calls.

This parameter is no longer needed; it was originally introduced
because Gerrit core needed to patch JGit libraries for GWT, and
this was not possible when they were signed. Now we don't use GWT
any more, so it's not necessary.

Change-Id: I622f2e52849a8d734aa38fe935f8d5d9c73e4a7d
2 files changed