fix missing import

web_app/gnss_rproxy_server.py

@@ -22,7 +22,7 @@
 from flask_login import LoginManager, login_user, logout_user, login_required, current_user, UserMixin
 from wtforms.validators import ValidationError, DataRequired, EqualTo
 import urllib
-#import gunicorn.app.base
+import gunicorn.app.base
 
 from werkzeug.security import generate_password_hash
 from werkzeug.security import check_password_hash