Fixed issue with not being able to disable the web interface

[prssn]

Current master gives the following exception:

sinopia/lib/index.js:93
    next( Error[404]('web interface is disabled in the config file') )
    ^
ReferenceError: next is not defined

[rlidwka]

Merged in c49b069 with one difference (endpoint should be /, not /*).

Thanks!