Only first middleware is ran through decorator

[seb-b]

If multiple middleware are added to the register_query_field, only the first one is ran e.g.

class FistMiddleware(object):
   def resolve(self, next, root, info, **args):
        print("Running first")
        return next(root, info, **args)
        
class SecondMiddleware(object):
   def resolve(self, next, root, info, **args):
        print("Running second")
        return next(root, info, **args)
        
 @register_query_field("demo", middleware=[FistMiddleware, SecondMiddleware])
 class Demo(models.Model):
      ....

Then the output is only 'Running first'. Switching the order means only second is outputted.

I think it's because of this line here where only the first field_middleware is returned in the loop instead of yielding all of them.

[zerolab]

@seb-b that is a great catch. Do you have time to submit a PR?