Fix SliceAdder create new chart link

superset-frontend/src/dashboard/components/SliceAdder.jsx

@@ -28,6 +28,7 @@ import { Select } from 'src/components';
 import Loading from 'src/components/Loading';
 import Button from 'src/components/Button';
 import Icons from 'src/components/Icons';
+import { ensureBasePath } from 'src/utils/pathUtils';
 import {
   LocalStorageKeys,
   getItem,
@@ -202,8 +203,8 @@ class SliceAdder extends Component {
       .filter(slice =>
         showOnlyMyCharts
           ? (slice.owners &&
-              slice.owners.find(owner => owner.id === this.props.userId)) ||
-            (slice.created_by && slice.created_by.id === this.props.userId)
+            slice.owners.find(owner => owner.id === this.props.userId)) ||
+          (slice.created_by && slice.created_by.id === this.props.userId)
           : true,
       )
       .filter(createFilter(searchTerm, KEYS_TO_FILTERS))
@@ -330,7 +331,7 @@ class SliceAdder extends Component {
             buttonSize="xsmall"
             onClick={() =>
               window.open(
-                `/chart/add?dashboard_id=${this.props.dashboardId}`,
+                ensureBasePath(`/chart/add?dashboard_id=${this.props.dashboardId}`),
                 '_blank',
                 'noopener noreferrer',
               )