fixed test for visual c++

tests/file_log.cpp

@@ -215,10 +215,9 @@ TEST_CASE("rotating_file_sink::calc_filename3", "[rotating_file_sink]]")
 
 
 
-
-
 // regex supported only from gcc 4.9 and above
-#if !(__GNUC__ <= 4 && __GNUC_MINOR__ < 9)
+#if defined (_MSC_VER) || !(__GNUC__ <= 4 && __GNUC_MINOR__ < 9)
+#include <regex>
 TEST_CASE("daily_file_sink::default_daily_file_name_calculator1", "[daily_file_sink]]")
 {
     // daily_YYYY-MM-DD_hh-mm.txt

tests/includes.h

@@ -6,10 +6,6 @@
 #include <ostream>
 #include <chrono>
 #include <exception>
-// regex supported only from gcc 4.9 and above
-#if !(__GNUC__ <= 4 && __GNUC_MINOR__ < 9)
-#include <regex>
-#endif
 #include "catch.hpp"
 #include "utils.h"