switching from safe to normal modes.
This way both keep-alive safety network implementation and virtual
(testing mode) could co-exists together.

See merge request !29

See merge request !28

See merge request !27

See merge request !26

See merge request !25

coupler exposes only 2 in the information mode.
Thus until we extend information mode be consistent here, too.

This reverts commit f20868bb.

we support only two I2C slaves thus be consistent here, too.