minor #1109 Remove duplicate assert (OskarStark)

This PR was merged into the 2.x branch.

Discussion
----------

Remove duplicate assert

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | no
| Tickets       | --
| License       | MIT

Commits
-------

904af5d Remove duplicate assert

Author: weaverryan

src/Autocomplete/tests/Functional/AutocompleteFormRenderingTest.php

@@ -65,7 +65,6 @@ public function testCategoryFieldSubmitsCorrectly()
             ->assertElementCount('#product_category_autocomplete option', 1)
             ->assertNotContains('First cat')
 
-            ->assertNotContains('First cat')
             ->post('/test-form', [
                 'body' => [
                     'product' => ['category' => ['autocomplete' => $fooCat->getId()]],