Timezone should set the Time Format for a new user setup

[NicolasWeb]

Is your feature request related to a problem? Please describe.
As a new user, I'm requested by the setup wizard to set my Timezone. Then, I have to update my Time Format in the settings if they don't match my Timezone/Language/Capital.

Describe the solution you'd like
Setting the Timezone should set the Time Format (Ex. Paris => 24h)