second pass for matrix's unconnected pairs

[nilsnolde]

Discovered in TomTom data, couldn't find a proper example in OSM for this. The same request works with OSM which might just be because in OSM there's a few more ways in that not_thru region to carry it over the 256 node limit beyond which we assume not_thru = false. But that's just a guess so far. Need to investigate further.

[nilsnolde]

Nope, it's not that.. In fact it's a very bad case, where both trees hit a different no_thru edge. /route only works on a second pass as well, after disabling no_thru. 2 things we should do anyways, both of which would make this matrix call work:

1. set not_thru for all edges in region #3812: mark all edges inside a no_thru region
2. Re-run the matrix only for unconnected pairs in a second pass, just like /route.

Both should be done eventually. I'd prefer to do 2. first, it'd have a bigger impact for matrix, also destonly, hierarchy limit relaxing etc could be dealt with.