Renamed method parameter and removed some unused parameters to clarify the code.

The second parameter to the VippyConfig.prototype.active was named
'method' when in fact is it just a text string passed and used as the
'reason' for becoming inactive in the
VippyConfig.prototype.inactive_reason function.

This change renames the parameter to 'reason' to make the code easier to
understand.

Additionally, the prototype for the VippyConfig.prototype.inactive_reason function
included two parameters (v, method) which were unused.

This change removed the extra parameters.