Inkscape-specific attributes are not removed from groups

[MartijnCuppens]

Is there a reason why this data

svgo/plugins/_collections.js

Lines 2280 to 2296 in 0835859

	exports.editorNamespaces = [
	'http://sodipodi.sourceforge.net/DTD/sodipodi-0.dtd',
	'http://inkscape.sourceforge.net/DTD/sodipodi-0.dtd',
	'http://www.inkscape.org/namespaces/inkscape',
	'http://www.bohemiancoding.com/sketch/ns',
	'http://ns.adobe.com/AdobeIllustrator/10.0/',
	'http://ns.adobe.com/Graphs/1.0/',
	'http://ns.adobe.com/AdobeSVGViewerExtensions/3.0/',
	'http://ns.adobe.com/Variables/1.0/',
	'http://ns.adobe.com/SaveForWeb/1.0/',
	'http://ns.adobe.com/Extensibility/1.0/',
	'http://ns.adobe.com/Flows/1.0/',
	'http://ns.adobe.com/ImageReplacement/1.0/',
	'http://ns.adobe.com/GenericCustomNamespace/1.0/',
	'http://ns.adobe.com/XPath/1.0/',
	'http://schemas.microsoft.com/visio/2003/SVGExtensions/'
	];

is only removed from the svg root?

svgo/plugins/removeEditorsNSData.js

Lines 38 to 49 in 4822a44

	if (item.isElem('svg')) {
	item.eachAttr(function(attr) {
	if (attr.prefix === 'xmlns' && editorNamespaces.indexOf(attr.value) > -1) {
	prefixes.push(attr.local);
	// <svg xmlns:sodipodi="">
	item.removeAttr(attr.name);
	}
	});
	}

These attributes are sometimes added to groups like in bootstrap:
https://github.com/twbs/bootstrap/blob/7b2372f35319ce392cb3f6ddab7c2de879a8a354/assets/brand/bootstrap-outline.svg#L2

I think they can also be removed from all other elements?

[XhmikosR]

@TrySound would it be OK just dropping the if (item.isElem('svg')) check?