Created attachment 939490 [details]
sync plan error on localized UI

Description of problem:

When you try to add a syncronization plan - url:

https://your-sat6-host/sync_plans/new

and you have that the language of your Sat6 account is not English, because or your account set to "browser default" and the preferred languare is not english or if you explicitely set to a non english language, it fails.

Trying to submit and kind of frequency gives your the result of having the inteval field with a red board and the error message below:

non è incluso nella lista (italian localization"
is not included in the list (translated)

I've tried to force also spanish the result is the same, for daily, weekly or hourly interval.

Version-Release number of selected component (if applicable):
Satellite 6.0.4

How reproducible:
Set a non english language for the UI and try to add a syncronization plan

Actual results:
Failure and message "is not included in the list".

Expected results:
To be added without error.