[2.0.20] Train signal upgrade/ghost in remote view plays wrong sound

[burninghey]

When building a rail signal ghost at existing signals in map view, issueing an "upgrade order" with the other type (rail signal <-> rail chain signal) wrong sound effect is played

[Donion]

Adding to the report, if you keep building the same signal on the same spot it will cycle between placing a ghost and making an upgrade request.
The sound is just a side effect of the buildability logic.