BUG corrupted configuration if power loss during write

[rusefi]

tomiata has reproduced corrupted flash configuration by turning power off while burning config

we need to keep two copies of configuration in flash so that at least one is OK

See http://rusefi.com/forum/viewtopic.php?f=5&t=1145&p=22145&hilit=reliability#p22137

Reported by: rusefi

[rusefi]

FLASH_ADDR_SECOND_COPY

Original comment by: rusefi

[rusefi]

New behavior: two copies are written into flash on each burn. If CRC validation fails for the first (primary) copy "Reading second configuration copy" message is displayed and second copy is read.

#11504

Original comment by: rusefi

[rusefi]

Stefan reports wiped out configuration on tuning engine off after auto-tune with a laptop

See http://rusefi.com/forum/viewtopic.php?f=3&t=1076&p=24889#p24889

[mck1117]

this was fixed in #1123