this change was made so that if you choose an entity type, then choose the "Please Select" option the entity type gets reset and so now if you choose another type the form will actually be shown
Fixed Issues (if relevant)
magento-engcom/import-export-improvements#64: Export UI is absent after reselecting entity type
Manual testing scenarios
Go to System -> Export in Admin Pane
Select for example Products entity type
Select "- Please Select -" option of Entity Type dropdown
Repeat step 2
Contribution checklist
[ ] Pull request has a meaningful description of its purpose
[ ] All commits are accompanied by meaningful commit messages
[ ] All new or changed code is covered with unit/integration tests (if applicable)
[ ] All automated tests passed successfully (all builds on Travis CI are green)
Description
Fixed Issues (if relevant)
Manual testing scenarios
Contribution checklist