[BUG: #249] userspace/libwr: don't toggle i2c pins before soft reset

After reset of the CPU (ARM) GPIO pins are set as input. During
configuration they were set to 0, which had a meaning to the i2c
transfer if the last transfer before reset was not completed (e.g. by
the switch restart).

Signed-off-by: Adam Wujek <dev_public@wujek.eu>