Invalid epipole check in match_for_triangulation

[adelpit]

The epipole check is being performed here even if reproject_to_bearing returns false and epiplane_in_keyfrm_2 is invalid. This can happen for, for example, perspective cameras when the epipole is not visible. The resulting value of epiplane_in_keyfrm_2 is not normalized which can cause a significant number of potential matches to fail this check.

The fix is in this PR: #525