If the context is cancelled `.NotificationUnreadCount` in a template can
cause an infinite loop with `ctx.ServerError()` being called, which
creates a template that then calls `.NotificationUnreadCount` calling
`GetNotificationCount()` with the cancelled context resulting in an
error that calls `ctx.ServerError`... and so on...
This PR simply stops calling `ctx.ServerError` in the error handler code
for `.NotificationUnreadCount` as we have already started rendering and
so it is too late to call `ctx.ServerError`. Additionally we skip
logging the error if it's a context cancelled error.
Fix #19793
Signed-off-by: Andrew Thornton <art27@cantab.net>
Co-authored-by: techknowlogick <techknowlogick@gitea.io>
93ab90743d