Fix: Working outside of request context

Author: dhanababum

flask_restx/marshalling.py

@@ -5,7 +5,7 @@
 from functools import wraps
 from six import iteritems
 
-from flask import request, current_app, has_app_context
+from flask import request, current_app, has_app_context, has_request_context
 
 from .mask import Mask, apply as apply_mask
 from .utils import unpack
@@ -247,7 +247,7 @@ def __call__(self, f):
  def wrapper(*args, **kwargs):
  resp = f(*args, **kwargs)
  mask = self.mask
- if has_app_context():
+ if has_app_context() and has_request_context():
  mask_header = current_app.config["RESTX_MASK_HEADER"]
  mask = request.headers.get(mask_header) or mask
  if isinstance(resp, tuple):