PEP8: fix E302: expected 2 blank lines, found 1

Signed-off-by: Joe Guo <joeg@catalyst.net.nz>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>
Reviewed-by: Douglas Bagnall <douglas.bagnall@catalyst.net.nz>

python/samba/netcmd/sites.py

@@ -221,6 +221,7 @@ class cmd_sites_subnet(SuperCommand):
         "set-site": cmd_sites_subnet_set_site(),
     }
 
+
 class cmd_sites(SuperCommand):
     """Sites management."""
     subcommands = {}