Include config.h and port.h for strncasecmp() in MSVC port.

diff --git a/dlls/comctl32/string.c b/dlls/comctl32/string.c
index 45163fe..c0bcdb3 100644
--- a/dlls/comctl32/string.c
+++ b/dlls/comctl32/string.c
@@ -22,6 +22,9 @@
  *
  */
 
+#include "config.h"
+#include "wine/port.h"
+
 #include <stdarg.h>
 #include <string.h>
 #include <stdlib.h> /* atoi */