jsx-no-duplicate-props ignore case fix (#7230)

Co-Authored-By: Ian Schmitz <ianschmitz@gmail.com>

Author: rommguy

packages/eslint-config-react-app/index.js

@@ -249,7 +249,7 @@ module.exports = {
     // https://github.com/yannickcr/eslint-plugin-react/tree/master/docs/rules
     'react/forbid-foreign-prop-types': ['warn', { allowInPropTypes: true }],
     'react/jsx-no-comment-textnodes': 'warn',
-    'react/jsx-no-duplicate-props': ['warn', { ignoreCase: true }],
+    'react/jsx-no-duplicate-props': 'warn',
     'react/jsx-no-target-blank': 'warn',
     'react/jsx-no-undef': 'error',
     'react/jsx-pascal-case': [