[Admin] Not possible to edit city code to 1

[Tuscann]

Which area(s) of Podkrepi.bg are affected?

Desktop layout

Describe the Bug

Not possible to edit city code to 1

To Reproduce

1. Open admin https://dev.podkrepi.bg/admin/cities
2. Click "Редактирай"
3. Add for field "Име" value 1@e
4. Add for field "Пощенски код" value 1
5. Click on button "Изпрати"
6. Observe the issue

Error message "Възникна грешка! Моля опитайте отново по-късно. "

Expected Behavior

Change name of city

Which browser are you using? (if relevant)

Vivaldi

[Tuscann]

Can we add more easy to understand error for the user. Add "Пощенски код" with only 3 number (100) not four. This general error not speak to end user that problem is add 4 digits for Postal code.