Issue #339: 0.4.0: i18n.enable should be 18n.enabled (conservancy/kallithea)

[Edmund Wong]

New issue 339: 0.4.0: i18n.enable should be 18n.enabled
https://bitbucket.org/conservancy/kallithea/issues/339/040-i18nenable-should-be-18nenabled

Edmund Wong:

Upgrading to 0.4.0, I noticed that the option as shown in the description for i18n are:


## Internationalization (see setup documentation for details)
## By default, the language requested by the browser is used if available.
#i18n.enable = false
## Fallback language, empty for English (valid values are the names of subdirectories in kallithea/i18n):
#i18n.lang = en_US.UTF-8
i18n.enable = false

But when I restart the web server and reload the page, I get this in the log:
```
[Mon Apr 01 09:19:48 2019] [error] 2019-04-01 09:19:48.883 DEBUG [tg.configuration.milestones] environment_loaded milestone reached
[Mon Apr 01 09:19:48 2019] [error] 2019-04-01 09:19:48.884 DEBUG [tg.appwrappers.i18n] i18n enabled: True -> {'lang': None, 'enable': 'false', 'no_session_touch': False, 'lang_session_key': 'tg_lang', 'enabled': True}
```

Clearly this should be "i18n.enabled = false", and changing that in my.ini, I get:
```
[Mon Apr 01 09:21:13 2019] [error] 2019-04-01 09:21:13.423 DEBUG [tg.appwrappers.i18n] i18n enabled: False -> {'lang': None, 'no_session_touch': False, 'lang_session_key': 'tg_lang', 'enabled': False}
```