use unordered_map_string_key for common header storage in httpfs_v2

Signed-off-by: Coldwings <[email protected]>

fs/httpfs/httpfs_v2.cpp

@@ -103,7 +103,7 @@ class HttpFs_v2 : public fs::IFileSystem {
 class HttpFile_v2 : public fs::VirtualReadOnlyFile {
 public:
     std::string m_url;
-    std::unordered_map<std::string, std::string> m_common_header;
+    unordered_map_string_key<std::string> m_common_header;
     HttpFs_v2* m_fs;
     struct stat m_stat;
     uint64_t m_stat_gettime = 0;