Update to 0.9.6.12

This release fixes some bugs in translation of words with non-ASCII
characters.

Release notes:

• https://github.com/soimort/translate-shell/releases/tag/v0.9.6.11
• https://github.com/soimort/translate-shell/releases/tag/v0.9.6.12

Also, update LICENSE.

PR: 250004
Approved by: maintainer timeout
MFH: 2020Q4 (runtime bugfix)