[parser] force filter to return a list in check_version.
[parser] force filter to return a list in check_version.

In python3, filter returns an interator hence the if filter(): fails because filter won't be [] but an interator.

This patch does what 2to3 does, meaning forcing filter to return a list. Therefore, check_version will have the same
behaviour between both versions.

DoomTaper/ptp,owtf/ptp