Language chooser is broken with `prefix_default_language=False`

[julianwachholz]

Django version
1.9 and up

Current behavior (bug description)

• In a Django project with i18n_patterns(..., prefix_default_language=False) the language picker will not be shown unless the user is already on a non-default language.
• When using the language chooser to go back to the default language, it gets hidden.

Expected behavior

• Language chooser should work the same as with with prefix_default_language=True.

[fabiocaccamo]

@julianwachholz thank you for reporting this issue!

[fabiocaccamo]

@julianwachholz you can upgrade to 0.27.0 version, thanks again for the PR!