s4:torture/smb2: remove useless 'smb2.multichannel.leases.test4'

s4:torture/smb2: remove useless 'smb2.multichannel.leases.test4'

Having a test that would only pass against Samba makes things way
to complex, they're already complex and we should try to behave
like windows as much as possible.

The next commit will add a better test that will work against Windows
Servers and the future Samba servers.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=11897

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Reviewed-by: Günther Deschner <gd@samba.org>