Remove unused header

Change-Id: I147664c3d181ba8ec535c7cddcb5c714e05616ea
Signed-off-by: Ed Tanous <ed@tanous.net>
diff --git a/test/http/utility_test.cpp b/test/http/utility_test.cpp
index 20af871..411eceb 100644
--- a/test/http/utility_test.cpp
+++ b/test/http/utility_test.cpp
@@ -1,8 +1,6 @@
 
 #include "utility.hpp"
 
-#include <bits/basic_string.h>
-
 #include <boost/system/result.hpp>
 #include <boost/url/parse.hpp>
 #include <boost/url/url.hpp>