Add a new LockSet unittest
Add a new LockSet unittest

This test checks the LockSet behaviour when an empty list is passed.
The current behaviour is expected, but since this is a corner case,
we're safer to keep it under a check, and if we need a different one
monitor that everything is as we expect it to be.

Reviewed-by: imsnah

dimara/ganeti,bitemyapp/ganeti,apyrgio/ganeti,ganeti-github-testing/ganeti-test-1,ganeti-github-testing/ganeti-test-1,andir/ganeti,apyrgio/snf-ganeti,ganeti/ganeti,yiannist/ganeti,grnet/snf-ganeti,apyrgio/ganeti,mbakke/ganeti,dimara/ganeti,leshchevds/ganeti,apyrgio/snf-ganeti,onponomarev/ganeti,mbakke/ganeti,andir/ganeti,ganeti/ganeti,yiannist/ganeti,andir/ganeti,yiannist/ganeti,leshchevds/ganeti,leshchevds/ganeti,onponomarev/ganeti,ganeti/ganeti,grnet/snf-ganeti,mbakke/ganeti,bitemyapp/ganeti