Update README.md on Qt sample

Author: Beatriz Rizental

samples/qt/README.md

@@ -35,7 +35,7 @@ pip3 install -r requirements.txt # Install glean_parser
 
 ```bash
 glean_parser translate src/App/metrics.yaml src/App/pings.yaml -f javascript -o src/App/generated \
---option platform=qt --option version="0.24"
+--option platform=qt --option version="0.31"
 ```
 
 5. Build the app: