[1.73][SSP/SSM] Networking Cable doesn't remove peripherals

This is a bit of a silly bug to report as normally it wouldn't happen but it, er, bugged me.

Version:
1.73 single player. I would presume it happens everywhere

Description:
When removing a peripheral connected to a wired modem using setblock, a ghost peripheral is created and you can still call methods on the peripheral.

Expected Result:
The peripheral wouldn't be accessible any more.

Reproduction Steps:

• Place down a peripheral and a computer and attach them both with wired modems & cable
• Activate both modems
• Run peripheral.getNames().
• Execute /setblock ~1 ~ ~ minecraft:stone whilst standing next to the peripheral.
• Run peripheral.getNames(). There is no change. You can also do peripheral.call(…) as well.

I've just done some more testing and there is a similar bug when breaking modems:

Description:
Breaking a peripheral next to a modem breaks the modem as expected, but when replacing the modem it is still on, detach isn't called on the peripheral, and it can still be accessed on computers.

Expected Result:
Detach is called, the modem turns off and computers refresh their peripheral list.

Reproduction steps:

• Place peripheral
• Attach modem and turn it on
• Break peripheral
• Place normal block in its place
• Place modem back on it
• It is still on

Screenshots: