fix signature generation failing under win32

tizzybec

2019-06-12 f0bab602c0d361f66a112e5a2db312b0da7dcd55

 src/library/pc-identifiers.c

@@ -179,7 +179,7 @@
      if (use_label) {
         if (diskInfos[i].label[0] != 0) {
            memset(identifiers[j], 0, sizeof(PcIdentifier)); //!!!!!!!
            strncpy(identifiers[j], diskInfos[i].label,
            strncpy((char*)identifiers[j], diskInfos[i].label,
                  sizeof(PcIdentifier));
            j++;
         }