Message about "Debug is not supported" displayed at the end of the build

[fpistm]

A post build script is executed to copy the correct openocd.cfg to the build path.
Anyway, since #2409 debug configurations changed and this step is useless.

Example of message:
No /local/home/<username>/.arduino15/packages/STMicroelectronics/hardware/stm32/2.8.1/variants/STM32WBxx/openocd.cfg available. Debug is not supported.

The message can be safely ignored as it is no more linked to the debug configuration.