Bug Frontend in messaging module, when edit an existing mail. The modification of start or end date fall into an endless loop.
A collision existed between the yup form validation and the integrated KeyboardDateTimePicker format validation process. To be coherent with the existing code, I just removed the format validation of KeyboardDateTimePicker. The date validation is rightfully made by the existing yup form validation method. A tiny difference will be introduce, the abbility to write a false date or time, like more than 60 seconds, or minutes. Able to write it, but not able to validate the form.
Closes #716 (closed)