contribs: fixed correct package selection for x86_64 on Darwin broken in...

contribs: fixed correct package selection for x86_64 on Darwin broken in [c1bc979e]
Signed-off-by: Felix Paul Kühne <fkuehne@videolan.org>

extras/contrib/bootstrap

@@ -194,7 +194,7 @@ case $HOST in
         RANLIB="ranlib"
         AR="ar"
         STRIP="strip"
-        DISTRO=darwin
+        DISTRO=darwin64
         if test -e /Developer/SDKs; then
             echo "SDKs found. Everything is fine." >&2
         else