package.json: Pin down eslint-plugin-react

See  jsx-eslint/eslint-plugin-react#2728

Closes #14415

Author: marusak

package.json

@@ -64,7 +64,7 @@
     "eslint-plugin-import": "^2.16.0",
     "eslint-plugin-node": "^8.0.1",
     "eslint-plugin-promise": "^4.0.1",
-    "eslint-plugin-react": "^7.12.4",
+    "eslint-plugin-react": "7.20.3",
     "eslint-plugin-standard": "^4.0.0",
     "exports-loader": "~0.6.3",
     "extend": "~3.0.0",