fix dup_filter_sink lose source_loc

[zydxhs]

Hi, dup_filter_sink lose the source_loc, when I use it like this:

auto dup_filter = std::make_shared<spdlog::sinks::dup_filter_sink_st>(std::chrono::seconds(5));
dup_filter->set_sinks(spdlog::default_logger()->sinks());
spdlog::default_logger()->sinks() = {std::move(dup_filter)};
spdlog::default_logger()->set_pattern("%Y-%m-%d %H:%M:%S.%e %^%l%$ %t [%s:%#:%!] %v");

for (int i = 0; i < 5; ++i) { SPDLOG_LOGGER_INFO(spdlog::default_logger_raw(), "duplicate log"); }
SPDLOG_LOGGER_INFO(spdlog::default_logger_raw(), "different log");

It's output has none filename/line/functionname but [::]:

2022-11-22 14:43:54.773 info 13089 [main.cpp:126:test] duplicate log
2022-11-22 14:43:54.773 info 13089 [::] Skipped 4 duplicate messages..
2022-11-22 14:43:54.773 info 13089 [main.cpp:127:test] different log

[gabime]

Thanks @zydxhs