The MSVC detects mismatch of const qualifiers in cfg_map_{first,next}clause
functions just in BIND 9.11. As this is harmless in this particular
case, just disable the warning for these two functions.
The warnings reported:
lib\isccfg\parser.c(2160): warning C4090: '=': different 'const' qualifiers
lib\isccfg\parser.c(2184): warning C4090: '=': different 'const' qualifiers