Fix: DOMTokenList error when removing section class

[minthemiddle]

• First add a section styling like p-2
• Then remove it with p-0
• It works, but you get an error in the console

Uncaught DOMException: Failed to execute 'add' on 'DOMTokenList': The token provided must not be empty. at addComponentClass

• This is because we pass an empty string in the <option>