Radio buttons on dialogs cause an error in IE quirks mode

[Teresa Monahan]

To reproduce add a radio button element to any dialog e.g.

{
	type : 'radio',
	id : 'type',
	required : true,
	'default' : 'one',
	items :
	[
		[ 'Radio1', 'one' ],
		[ 'Radio2', 'two' ]
	]
}

Load the page in IE in quirks mode and open the dialog.

Problem: The browser throws the following error:

'children[...].align' is null or not an object

This error can be traced back to line 2538 of plugins/dialog/plugin.js:

// In IE Quirks alignment has to be done on table cells. (#7324)
if ( CKEDITOR.env.ie && CKEDITOR.env.quirks && children[ i ].align )

[Jakub Ś]

Reproducible form rev [6942] in IE Quirks.

[Jakub Ś]

Error message:
Message: 'children[...].align' is null or not an object
Line: 2450
URI: ckeditor/_source/plugins/dialog/plugin.js

[Garry Yao]

Fixed with [7108].