Enable user warnings in tests to be able to fix them.

test/static_vector_test.cpp

@@ -7,7 +7,6 @@
 // Use, modification and distribution is subject to the Boost Software License,
 // Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
 // http://www.boost.org/LICENSE_1_0.txt)
-#include <boost/container/detail/config_begin.hpp>
 #include <boost/core/lightweight_test.hpp>
 #include <boost/core/no_exceptions_support.hpp>
 #include <boost/container/vector.hpp>
@@ -824,4 +823,3 @@ int main(int, char* [])
    return boost::report_errors();
 }
 
-#include <boost/container/detail/config_end.hpp>