message: fix: resolve crash when exception is thrown with incorrect format string
diff: @@ -493,7 +493,7 @@ namespace Nextclade {
  ErrorTreeNodeTypeInvalid::ErrorTreeNodeTypeInvalid(const json& node)
  : std::runtime_error(fmt::format(
  - "When accessing Tree Node type: the type is invalid. Expected a string, one of { \"Reference\", \"New\" },"
  + "When accessing Tree Node type: the type is invalid. Expected a string, one of {{ \"Reference\", \"New\" }},"
  "but got \"{}\". This is an internal issue. Please report this to developers, providing data and parameters "
  "you used, in order to replicate the error.",
  node.dump())) {}
  