Try to run ChipErase on UPDI even if return code is -67

Fixes arduino/ArduinoCore-megaavr#33

Author: facchinm

main.c

@@ -1046,7 +1046,7 @@ int main(int argc, char * argv [])
       rc = avr_signature(pgm, p);
       if (rc != 0) {
         // -68 == -(0x44) == -(RSP3_FAIL_OCD_LOCKED)
-        if ((rc == -68) && (p->flags & AVRPART_HAS_UPDI) && (attempt < 1)) {
+        if ((rc == -68 || rc == -67) && (p->flags & AVRPART_HAS_UPDI) && (attempt < 1)) {
           attempt++;
           if (pgm->read_sib) {
              // Read SIB and compare FamilyID