editors/nvi2: Update to 2.2.0

Switch to the release version, there are no functional changes
compared to 2.1.3.g2020801.

Documented changes between 2.1.3 and 2.2.0:

https://github.com/lichray/nvi2/releases/tag/v2.2.0

• Vim-style expandtab option
• Provides Turkish translation
• Backspace now deletes \ rather than being escaped
• T during motion commands is now VI-compatible
• Encoding related fixes, such as UTF-8 detection
• Fixed a number of memory management issues