pipe connectors get autodeleted

Issue description

When two pipe connectors are placed, then a pipe is run between the two, the connectors get deleted.

This is very annoying when building a manifold, as i prefer to start by placing the buildings first, then the connectors, then the pipes.

Reproduction steps

1. Place two pipe connectors in the world
2. Connect a pipe between them
3. observe the pipe connectors get deleted

Game version and build number

v0.7.9a(b500)

Operating system

Linux

Attachments

Duplicate of Pipe connector disappears when connecting pipe