cancel dnd if original target is content editable

Sortable.js

@@ -326,6 +326,10 @@
 				return; // only left button or enabled
 			}
 
+			// cancel dnd if original target is content editable
+			if (originalTarget.isContentEditable) {
+				return;
+			}
 
 			target = _closest(target, options.draggable, el);