[gluster] remove unnecessary default_enabled()

Signed-off-by: Bryn M. Reeves <bmr@redhat.com>
[satellite] make plugin default enabled

Signed-off-by: Bryn M. Reeves <bmr@redhat.com>
[soundcard] make plugin default enabled

Signed-off-by: Bryn M. Reeves <bmr@redhat.com>
[sosreport] fix whitespace errors

Signed-off-by: Bryn M. Reeves <bmr@redhat.com>
[sosreport] change description of non-default plugins

Plugins are currently listed as 'not default' if the plugin's
default_enabled() method evaluates to False:

 sendmail             inactive       sendmail service
 snmp                 inactive       Simple network management protocol
 soundcard            not default    Sound devices
 squid                inactive       Squid caching proxy

It sounds odd and it looks ugly in the plugin listing. Change the
description to 'optional':

 sendmail             inactive       sendmail service
 snmp                 inactive       Simple network management protocol
 soundcard            optional       Sound devices
 squid                inactive       Squid caching proxy

Signed-off-by: Bryn M. Reeves <bmr@redhat.com>