{car, hgv}-directions and car-matrix find route, but hgv-matrix doesn't

[koebi]

This was reported in the forum - for the same locations, directions finds car and hgv routes, and matrix finds a car-matrix, but no hgv-matrix.

[aoles]

I think the problem has been introduced in #1126. This would explain why the issue is only observed on master and not with the current release. It needs further investigation at which point the new approach fails and whether it doesn't work with CH routing in general, or maybe the issue is specific to RPHAST matrix algorithm.