Remove support for "enabled" in config file

[mountaindude]

In the early days of Butler's life the config file used the property "enabled" to enable/disable various features.
That was later changed to "enable" everywhere in the config file, but Butler has continued to accept "enabled" during the last several years.

As part of cleaning up the config file the support for "enabled" in the config file will be removed as part of this ticket.
Going forward only the "enable" property will be recognised in the Butler config file.