regression test for bug 3172
fix for bug 3172
Revert "fix for bug 3172"

This reverts commit ed2cdb71e5821db85b57cf60d88689c2bf32aeeb.
fix for bug 3172
regression test for bug 3172
fix for bug 3172
Revert "fix for bug 3172"

This reverts commit ed2cdb71e5821db85b57cf60d88689c2bf32aeeb.
fix for bug 3172
Merge branch 'bug_3172' of https://github.com/elmarb/opencv into bfmatcher_fix;
use different fix for the problem, embedded right into the BFMatcher.
Merge pull request #3238 from vpisarev:bfmatcher_fix