Avoid Firefox bug with label editing. Fixes #2332

src/dom_components/view/ComponentLabelView.js

@@ -1,3 +1,5 @@
 import ComponentLinkView from './ComponentLinkView';
 
-export default ComponentLinkView.extend({});
+export default ComponentLinkView.extend({
+  tagName: 'span' // Avoid Firefox bug with label editing #2332
+});