Upgrade mime-types-data to 3.2019.0331

This saves some disk space by matching the version used in Gitaly.

Only minor changes:

• https://github.com/mime-types/mime-types-data/blob/master/History.md
• https://github.com/mime-types/mime-types-data/compare/v3.2018.0812..v3.2019.0331

This fixes a regression in mime-types-data in the spec: https://github.com/mime-types/mime-types-data/pull/20