Fix handling of output annotations with generics under Python 3.7

Author: elprans

azure/functions_worker/bindings/queue.py

@@ -102,8 +102,8 @@ class QueueMessageOutConverter(meta.OutConverter, binding='queue'):
     def check_output_type_annotation(cls, pytype: type) -> bool:
         valid_types = (azf_abc.QueueMessage, str, bytes)
         return (
-            issubclass(pytype, valid_types) or
-            meta.is_iterable_type_annotation(pytype, valid_types)
+            meta.is_iterable_type_annotation(pytype, valid_types) or
+            (isinstance(pytype, type) and issubclass(pytype, valid_types))
         )
 
     @classmethod

azure/functions_worker/functions.py

@@ -151,7 +151,8 @@ def add_function(self, function_id: str,
             else:
                 param_py_type = param_anno
 
-            if param_has_anno and not isinstance(param_py_type, type):
+            if (param_has_anno and not isinstance(param_py_type, type) and
+                    not typing_inspect.is_generic_type(param_py_type)):
                 raise FunctionLoadError(
                     func_name,
                     f'binding {param.name} has invalid non-type annotation '