Fix incorrect logging of bailout to Open Circuit when using the best gas. This happened because the starting gas used for 'best gas' calculation was a diluent - in most cases not a problem as the same gas is also used as a bailout gas. Now use the 'first' open circuit gas configured as the starting point. Also fixes the problem of a custom bailout gas not being logged as such, and consequently not being shown as bailout in the on-device log.

Imported from Ac6/SystemWorkbench/plugins/fr.ac6.mcu.firmware_1.14.7.201711101414/resources/builtin/:
* File syscalls.c