The webservice that audio/libmusicbrainz3 interfaces with will cease operation
on 2018-08-01. Add upstream patch to use audio/libmusicbrainz5 for track lookup
operations instead.

Reviewed by: rakuco
Obtained from: KDE git repo
MFH: 2018Q3 (runtime fix)
Differential Revision: https://reviews.freebsd.org/D16536