message: Allow json.hpp to be used with gcc 4.8.5
  There are a few issues with this that prevent it from being accepted upstream but it's fine for how we use it.
diff: @@ -63,7 +63,7 @@ SOFTWARE.
  "unsupported Clang version - see https://github.com/nlohmann/json#supported-compilers"
  #endif
  #elif defined(__GNUC__)
  -#if (__GNUC__ * 10000 + __GNUC_MINOR__ * 100 + __GNUC_PATCHLEVEL__) < 40900
  +#if (__GNUC__ * 10000 + __GNUC_MINOR__ * 100 + __GNUC_PATCHLEVEL__) < 40805
  #error \
  "unsupported GCC version - see https://github.com/nlohmann/json#supported-compilers"
  #endif
  