fix image test after optimization

Author: maxsbelt

packages/react-scripts/fixtures/kitchensink/template/integration/webpack.test.js

@@ -86,7 +86,7 @@ describe('Integration', () => {
       doc = await initDOM('image-inclusion');
 
       expect(doc.getElementById('feature-image-inclusion').src).toMatch(
-        /^data:image\/jpeg;base64.+==$/
+        /^data:image\/jpeg;base64.+=$/
       );
     });