New scheduler - minutes fix

[jeernest]

STR
let's suppose that current time is 5:15pm

current behavior

1. create a new scheduler to run at 4:15pm - the form validation doesn't allow saving, because the time is in the past
2. create a new scheduler to run at 5:45pm - the form validation allows saving, because it is in the future, the StartDate is set to 6pm
3. create a new scheduler to run at 5:15pm - the form validation allows saving, because it is now, the StartDate is set to 5pm, which is in the past

expected bahavior
The form says that it rounds the minutes, so in case of current time, it should round the time to nearest hour in the future