[4.0] 2011a6b Use gmake as a fallback if make doesn't exist

[Lasse Karstensen]

commit 2011a6b2d87fae2042c6b5183ef41bb41a5b1bd1
Author: Lasse Karstensen <lkarsten at varnish-software.com>
Date:   Wed Jan 29 10:14:14 2014 +0100

    Use gmake as a fallback if make doesn't exist
    
    gmake doesn't exist on Linux servers.

diff --git a/autogen.des b/autogen.des
index a385c71..07afad4 100755
--- a/autogen.des
+++ b/autogen.des
@@ -18,7 +18,10 @@ rm -f configure
 # autoconf prior to 2.62 has issues with zsh 4.2 and newer
 export CONFIG_SHELL=/bin/sh
 
-env MAKE=gmake \
+if [ ! -x "/usr/bin/xmake" -a "x${MAKE}" == "x"]; then
+    export MAKE=gmake
+fi
+
 ./configure \
     --enable-developer-warnings \
     --enable-debugging-symbols \