Log Message:
Update ruby-gettext to 3.2.3.

## 3.2.3: 2017-06-24 {#version-3-2-3}

### Improvements

  * Disabled unmaintainable Ruby from CI.
    [GitHub#48][Reported by JP Hastings-Spital]

  * Supported `--enable-frozen-string-literal` `ruby` option.
    [GitHub#52][Reported by Pat Allan]

### Thanks

  * JP Hastings-Spital

  * Pat Allan