libmcrypt doesn't use C++ so remove the check.

Signed-off-by: Gustavo Zacarias <gustavo@zacarias.com.ar>

diff -Nura libmcrypt-2.5.8.orig/configure.in libmcrypt-2.5.8/configure.in
--- libmcrypt-2.5.8.orig/configure.in	2013-01-07 12:20:44.332200669 -0300
+++ libmcrypt-2.5.8/configure.in	2013-01-07 12:20:50.405390565 -0300
@@ -19,7 +19,6 @@
 
 AC_PROG_MAKE_SET
 
-AC_PROG_CXX
 AC_PROG_CC
 AC_PROG_CPP
 AC_PROG_INSTALL