Removed dead code from os.h

include/spdlog/details/os.h

@@ -107,16 +107,6 @@ inline std::tm gmtime() noexcept
     std::time_t now_t = time(nullptr);
     return gmtime(now_t);
 }
-//inline bool operator==(const std::tm &tm1, const std::tm &tm2) noexcept
-//{
-//    return (tm1.tm_sec == tm2.tm_sec && tm1.tm_min == tm2.tm_min && tm1.tm_hour == tm2.tm_hour && tm1.tm_mday == tm2.tm_mday &&
-//            tm1.tm_mon == tm2.tm_mon && tm1.tm_year == tm2.tm_year && tm1.tm_isdst == tm2.tm_isdst);
-//}
-//
-//inline bool operator!=(const std::tm &tm1, const std::tm &tm2) noexcept
-//{
-//    return !(tm1 == tm2);
-//}
 
 // eol definition
 #if !defined(SPDLOG_EOL)