Ignore the Content-Type header completely for @font-face.
This matches the previous default (network.mime.sniff off) behaviour in all but one case: we will now accept a font without a `Content-Type` header, which would previously have been ignored.
Ignore the Content-Type header completely for @font-face.
This matches the previous default (network.mime.sniff off) behaviour in all but one case: we will now accept a font without a `Content-Type` header, which would previously have been ignored.
