removes incomplete check. Without it autoconf will fail.
================================================================================
Index: configure.in
===================================================================
--- configure.in.orig
+++ configure.in
@@ -232,7 +232,7 @@ AC_ARG_WITH(libxml, [  --with-libxml=[PF
 if test "z$with_libxml" = "zno" ; then 
     AC_MSG_CHECKING(for libxml2 libraries >= $LIBXML_MIN_VERSION) 
     AC_MSG_ERROR(libxml2 >= $LIBXML_MIN_VERSION is required for $XMLSEC_PACKAGE)
-elif test "z$with_libxml" = "z" -a "z$PKG_CONFIG_ENABLED" = "zyes" ; then
+elif test "z$with_libxml" = "z" ; then
     PKG_CHECK_MODULES(LIBXML, libxml-2.0 >= $LIBXML_MIN_VERSION,
 	[LIBXML_FOUND=yes],
 	[LIBXML_FOUND=no])