Add information when user updated filters last time

[AdamWr]

It would be useful in case when users are reporting the same issue again and again, but didn't update filters.
For example, it happens usually with popular websites which often update anti-adblock script.
If we would know that user has not up to date filters, we could just close issue with the appropriate comment without checking it again.
I guess, it could be useful also in other situations.