$NetBSD$

Use PYTHON passed through from Makefile.

--- config/configure.orig	2013-12-20 09:43:15.000000000 +0000
+++ config/configure
@@ -42,7 +42,7 @@ if [ -z "$MAKE_VERSION" ]; then
 fi
 expr "$MAKE_VERSION" '>=' '3.81' || AC_FAIL "ERROR: $MAKE must be >= version 3.81"
 
-if test -z "$(bup_find_prog python '')"; then
+if test -z "$(bup_find_prog python "$PYTHON")"; then
     AC_FAIL "ERROR: unable to find python"
 fi
 
