format: don't assume alter_user or alter_network.

It is assumed when arguments and config parameters are merged.
Otherwise, it is not possible to set this option from the .cfg.

slapos/cli/format.py

@@ -35,13 +35,11 @@ class FormatCommand(ConfigCommand):
 
         ap.add_argument('--alter_user',
                         choices=['True', 'False'],
-                        default='True',
                         help='Shall slapformat alter user database'
                              ' (default: %(default)s)')
 
         ap.add_argument('--alter_network',
                         choices=['True', 'False'],
-                        default='True',
                         help='Shall slapformat alter network configuration'
                              ' (default: %(default)s)')