Fix #90: Create blank data when initial data is null

Author: bhch

src/editorState.js

@@ -25,7 +25,7 @@ export default class EditorState {
         if (typeof data === 'string' && data !== '')
             data = JSON.parse(data);
 
-        if (!data && data !== null) {
+        if (!data) {
             // create empty data from schema
             data = getBlankData(schema, (ref) => EditorState.getRef(ref, schema));
         } else {