avatars: Clean up now-irrelevant assumptions.

This x=x hack was removed in 3bd3173b1f.

zerver/views/upload.py

@@ -285,9 +285,10 @@ def serve_local_avatar_unauthed(request: HttpRequest, path: str) -> HttpResponse
         # We do not expect clients to hit this URL when using the S3
         # backend; however, there is no reason to not serve the
         # redirect to S3 where the content lives.
-        return redirect(
-            get_public_upload_root_url() + path + "?" + request.GET.urlencode(), permanent=True
-        )
+        url = get_public_upload_root_url() + path
+        if request.GET.urlencode():
+            url += "?" + request.GET.urlencode()
+        return redirect(url, permanent=True)
 
     local_path = os.path.join(settings.LOCAL_AVATARS_DIR, path)
     assert_is_local_storage_path("avatars", local_path)

zerver/views/users.py

@@ -312,11 +312,8 @@ def avatar(
         avatar_version = 1
         url = get_gravatar_url(email, avatar_version, medium)
 
-    # We can rely on the URL already having query parameters. Because
-    # our templates depend on being able to use the ampersand to
-    # add query parameters to our url, get_avatar_url does '?x=x'
-    # hacks to prevent us from having to jump through decode/encode hoops.
     assert url is not None
+    if request.META["QUERY_STRING"]:
         url = append_url_query_string(url, request.META["QUERY_STRING"])
     return redirect(url)