Fix Python 3.8 compatibility

Author: tulir

mautrix/__init__.py

@@ -1,4 +1,4 @@
-__version__ = "0.19.15"
+__version__ = "0.19.16"
 __author__ = "Tulir Asokan <[email protected]>"
 __all__ = [
     "api",

mautrix/appservice/as_handler.py

@@ -83,7 +83,9 @@ def _check_token(self, request: web.Request) -> bool:
             token = request.rel_url.query["access_token"]
         except KeyError:
             try:
-                token = request.headers["Authorization"].removeprefix("Bearer ")
+                token = request.headers["Authorization"]
+                if token.startswith("Bearer "):
+                    token = token[len("Bearer "):]
             except (KeyError, AttributeError):
                 self.log.trace("No access_token nor Authorization header in request")
                 return False