As a regression of MDL-55360, it was not possible to create new
workshops if the field "Submission grade to pass" or "Assessment grade
to pass" was left empty. The validation failed with "You must enter a
number here".
The fields submissiongradepass and gradinggradepass are always present
as we explicitly define them in the mod form. So the isset() condition
in the validation was useless and it did not allow to submit the form
with these fields empty.
Additionally, the unformat_float() returns null only if it receives
empty value on the input. Which can't happen in our case so I am
removing this condition to improve the readability of the code.
David Mudrák
cd830f4e2c