fix: Use weak etags instead of etag (fossasia#9)

We are not conforming to strong etags anyway and they are dropped
by cloudlare and nginx when response is compressed as it is not
hash of final output response

flask_rest_jsonapi/resource.py

@@ -111,7 +111,7 @@ def dispatch_request(self, *args, **kwargs):
 
         # ETag Handling
         if current_app.config.get('ETAG') == True:
-            etag = hashlib.sha1(resp.get_data()).hexdigest()
+            etag = f'W/"{hashlib.sha1(resp.get_data()).hexdigest()}"'
             resp.headers['ETag'] = etag
 
             if_match = request.headers.get('If-Match')