message: fix: Making chart update more truthful
  * Update index.jsx
  * Update superset-frontend/src/dashboard/components/Header/HeaderActionsDropdown/index.jsx
  * Update superset-frontend/src/dashboard/components/Header/HeaderActionsDropdown/index.jsx
  Fixing case
diff: @@ -158,7 +158,7 @@ class HeaderActionsDropdown extends React.PureComponent {
  switch (key) {
  case MENU_KEYS.REFRESH_DASHBOARD:
  this.props.forceRefreshAllCharts();
  - this.props.addSuccessToast(t('Data refreshed'));
  + this.props.addSuccessToast(t('Refreshing charts'));
  break;
  case MENU_KEYS.EDIT_PROPERTIES:
  this.props.showPropertiesModal();
  