Update Dockerfile

Dockerfile

@@ -22,4 +22,4 @@ RUN pip install -r requirements.txt
 # webserver, with one worker process and 8 threads.
 # For environments with multiple CPU cores, increase the number of workers
 # to be equal to the cores available.
-CMD exec gunicorn --bind 0.0.0.0:8080 --workers 1 --threads 8 --timeout 0 app:app
+CMD exec gunicorn --bind 0.0.0.0:7860 --workers 1 --threads 8 --timeout 0 app:app