django.contrib.messages.api: use HttpRequest instead of WSGIRequest (#73)

Its error messages explicitly note that an HttpRequest is required.
https://docs.djangoproject.com/en/2.1/_modules/django/contrib/messages/api/#add_message

Author: scop

django-stubs/contrib/messages/api.pyi

@@ -1,13 +1,12 @@
 from typing import Any, List, Optional, Union
 
 from django.contrib.messages.storage.base import BaseStorage
-from django.core.handlers.wsgi import WSGIRequest
 from django.http.request import HttpRequest
 
 class MessageFailure(Exception): ...
 
 def add_message(
-    request: Optional[WSGIRequest],
+    request: Optional[HttpRequest],
     level: int,
     message: str,
     extra_tags: str = ...,
@@ -16,12 +15,12 @@ def add_message(
 def get_messages(request: HttpRequest) -> Union[List[Any], BaseStorage]: ...
 def get_level(request: HttpRequest) -> int: ...
 def set_level(request: HttpRequest, level: int) -> bool: ...
-def debug(request: WSGIRequest, message: str, extra_tags: str = ..., fail_silently: Union[bool, str] = ...) -> None: ...
-def info(request: WSGIRequest, message: str, extra_tags: str = ..., fail_silently: Union[bool, str] = ...) -> None: ...
+def debug(request: HttpRequest, message: str, extra_tags: str = ..., fail_silently: Union[bool, str] = ...) -> None: ...
+def info(request: HttpRequest, message: str, extra_tags: str = ..., fail_silently: Union[bool, str] = ...) -> None: ...
 def success(
-    request: WSGIRequest, message: str, extra_tags: str = ..., fail_silently: Union[bool, str] = ...
+    request: HttpRequest, message: str, extra_tags: str = ..., fail_silently: Union[bool, str] = ...
 ) -> None: ...
 def warning(
-    request: WSGIRequest, message: str, extra_tags: str = ..., fail_silently: Union[bool, str] = ...
+    request: HttpRequest, message: str, extra_tags: str = ..., fail_silently: Union[bool, str] = ...
 ) -> None: ...
-def error(request: WSGIRequest, message: str, extra_tags: str = ..., fail_silently: Union[bool, str] = ...) -> None: ...
+def error(request: HttpRequest, message: str, extra_tags: str = ..., fail_silently: Union[bool, str] = ...) -> None: ...