Clicking the file delete action triggers upload dialog when dialog has error

How to reproduce

• To to edit form of a course info page
• For the course title image, upload a pdf
• Save the form
• => OK error appears
• Click the delete icon to remove the PDF
• => NOK: the file upload dialog appears again
• => NOK: file not deleted

The problem is the invisible file upload dialog that is not aware of the error icon. The error icon is also a bit strange in case the file upload preview is displayed, in that case the error icon is at the top close to the preview icon and not by the input field. 

The solution is to remove the error icon for the file upload element. The color and the error text is sufficient to see that there is an error, no icon needed.