[explore-v2] Fix edit datasource link for druid datasources (#1982)

* only add imgSrc key if choices contain an imgSrc

* handle table and druid edit links for datasource drop down

* fix linting

superset/assets/javascripts/explorev2/stores/fields.js

@@ -26,15 +26,20 @@ const TIME_STAMP_OPTIONS = [
   ['%H:%M:%S', '%H:%M:%S | 01:32:10'],
 ];
 
+const MAP_DATASOURCE_TYPE_TO_EDIT_URL = {
+  table: '/tablemodelview/edit',
+  druid: '/druiddatasourcemodelview/edit',
+};
+
 export const fields = {
   datasource: {
     type: 'SelectField',
     label: 'Datasource',
     clearable: false,
     default: null,
-    editUrl: '/tablemodelview/edit',
     mapStateToProps: (state) => ({
       choices: state.datasources || [],
+      editUrl: MAP_DATASOURCE_TYPE_TO_EDIT_URL[state.datasource_type],
     }),
     description: '',
   },