cubicweb-forgotpwd #4862475 Error if email is unknown [validation pending]

If the entered email does not exist in the database, we get a " global name 'ValidationError' is not defined " instead of a proper message.

prioritynormal
typebug
done in0.6.2
load1.000
load left0.000
closed by#8bc0f2347763 Import ValidationError
patchImport ValidationError [applied]