edge case for placing pipe connector

Issue description

I've only hit this rarely. I think it has to do with there being 3 pipes and one behind it -- so not much space for the pathfinder to find a path. this is reproducible though.

Reproduction steps

1. load save
2. open transports menu
3. in the three pipes intersection, click on either of the green arrows to make a pipe connector and it'll fail
4. now try clicking on the red pipe arrow twice and it'll work

Game version and build number

v0.6.2 (b327)

Operating system

Windows

Attachments

bug - click on green pipes, connector fails, click on red one twice and it works.save