Add missing config key

This sets the default so that automatic options are provided.

(cherry picked from commit 2473a04)

Author: pgjones

src/quart/app.py

@@ -241,6 +241,7 @@ class Quart(App):
             "PREFER_SECURE_URLS": False,
             "PRESERVE_CONTEXT_ON_EXCEPTION": None,
             "PROPAGATE_EXCEPTIONS": None,
+            "PROVIDE_AUTOMATIC_OPTIONS": True,
             "RESPONSE_TIMEOUT": 60,  # Second
             "SECRET_KEY": None,
             "SEND_FILE_MAX_AGE_DEFAULT": timedelta(hours=12),