configure: check for uintptr_t type

configure.ac

@@ -530,7 +530,7 @@ AC_CHECK_HEADERS([sys/socket.h sys/select.h netinet/in_systm.h netinet/in.h \
 # Check for other optional headers
 AC_CHECK_HEADERS([sys/msg.h sys/mman.h signal.h], [], [], [AC_INCLUDES_DEFAULT])
 
-AC_CHECK_TYPES([size_t, ssize_t, ptrdiff_t, intptr_t],[],[],
+AC_CHECK_TYPES([size_t,ssize_t,ptrdiff_t,intptr_t,uintptr_t],[],[],
   [[
 /* Keep in sync with src/mhd2/sys_base_types.h */
 #include <stdint.h> /* uint_fast_XXt, int_fast_XXt */