This fixes an issue where there server would start up fine even if NPC
types from a later build were found in the gruntwork file. Because of
the semantics of the C++ array indexing operator, the index into NPCData
in loadGruntworkPost() would silently create extra entries in the
nlohmann::json array, which would break future NPC type limit checks and
subsequently crash the server at the next invocation of /summonW, and
likely other places.
We fix this by refusing to start the server if any invalid NPC types are
found, because simply skipping them in the gruntwork file would silently
omit them from further writes to the gruntwork file, which would be
undesirable data loss.
dongresource
23ab908366