[BUG] G28 Command - Klipper - Aliases Pins

[Reubertt]

If you use aliases for the board pins you will have an error when executing command G28 it will homing the x and y axis, but when calling G28 Z you will have the following error in the web interface.

Internal error on command:"G28"

And the following error in the log.

msgproto.enumeration_error: Unknown value 'probe' in enumeration 'pin'

It's a simple bug for the user to fix, but I'm leaving it here in case they experience this or in case the dev wants to check.

[board_pins]
aliases:
    servo=PE6
    probe=PC2