esp32/machine_uart: Uninstall the UART driver before installing it.
esp32/machine_uart: Uninstall the UART driver before installing it.

To allow to create the same UART a second time without error.

MrSurly/micropython-esp32,SHA2017-badge/micropython-esp32,micropython/micropython-esp32,MrSurly/micropython-esp32,micropython/micropython-esp32,SHA2017-badge/micropython-esp32,MrSurly/micropython-esp32,micropython/micropython-esp32,MrSurly/micropython-esp32,micropython/micropython-esp32,MrSurly/micropython-esp32,SHA2017-badge/micropython-esp32,SHA2017-badge/micropython-esp32,SHA2017-badge/micropython-esp32,micropython/micropython-esp32