message: Fix use case_insensitive_map for headers
diff: #include "duckdb/common/file_system.hpp"
  #include "duckdb/common/pair.hpp"
  #include "duckdb/common/unordered_map.hpp"
  +#include "duckdb/common/case_insensitive_map.hpp"
  namespace duckdb_httplib_openssl {
  struct Response;
  @@ -11,7 +12,7 @@ class Client;
  namespace duckdb {
  -using HeaderMap = unordered_map<string, string>;
  +using HeaderMap = case_insensitive_map_t<string>;
  // avoid including httplib in header
  struct ResponseWrapper {
  