Log Message:
devel/ruby-gettext: update to 3.3.6

Update ruby-gettext to 3.3.6.

## 3.3.6: 2020-08-04 {#version-3-3-6}

### Improvements

  * erb: Added support for `-%>`.
    [GitHub#77][Reported by lremes]

  * Removed ChangeLog.
    [GitHub#76][Reported by Will Stephenson]

  * Don't assume `RbConfig::CONFIG["datadir"]` is available. For
    example, TruffleRuby doesn't provide it.

### Thanks

  * lremes

  * Will Stephenson