n_filter_resets_ not updated

[lvanroye]

Hello,

I think there might be a problem in the filter reset heuristics implementation. The n_filter_resets_ count never gets updated, such that the

      if (n_filter_resets_ < max_filter_resets_)

statement is always true.

Please let me know if I can propose a solution in the form of a PR.

Lander