Fix annotation

Author: asvetlov

aiohttp_jinja2/__init__.py

@@ -35,7 +35,7 @@
 _MethodHandler = Callable[[Any, web.Request], Awaitable[web.StreamResponse]]
 _ViewHandler = Callable[[Type[AbstractView]], Awaitable[web.StreamResponse]]
 _HandlerType = Union[_SimpleHandler, _MethodHandler, _ViewHandler]
-_TemplateReturnType = Awaitable[Union[web.StreamResponse, Mapping[str, Any]]]
+_TemplateReturnType = "Awaitable[Union[web.StreamResponse, Mapping[str, Any]]]"
 _SimpleTemplateHandler = Callable[[web.Request], _TemplateReturnType]
 _MethodTemplateHandler = Callable[[Any, web.Request], _TemplateReturnType]
 _ViewTemplateHandler = Callable[[AbstractView], _TemplateReturnType]