Removed backtrace feature

example/example.cpp

@@ -56,17 +56,6 @@ int main(int, char *[])
     spdlog::set_pattern("%+"); // back to default format
     spdlog::set_level(spdlog::level::info);
 
-    // Backtrace support
-    // Loggers can store in a ring buffer all messages (including debug/trace) for later inspection.
-    // When needed, call dump_backtrace() to see what happened:
-    spdlog::enable_backtrace(10); // create ring buffer with capacity of 10  messages
-    for (int i = 0; i < 100; i++)
-    {
-        spdlog::debug("Backtrace message {}", i); // not logged..
-    }
-    // e.g. if some error happened:
-    spdlog::dump_backtrace(); // log them now!
-
     try
     {
         stdout_logger_example();