Invalid epipole check in match_for_triangulation

[adelpit]

Re-posting this upstream issue here:

The epipole check for triangulating new points is being performed 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 upstream PR. It can be a very important fix if a perspective camera moves laterally so that the epipole is not in the field of view.