Its got nothing to do with security certificates expiring. The problem is that many websites now require TLS 1.2 (because TLS 1.2 is a lot more secure than the older TLS 1.0 standard) and the Maemo web browser doesn't support TLS 1.2. I have been trying to find a way to get TLS 1.2 support into the Maemo browser but so far have not had any success with my plans.