Allow using newer MacPorts neon.
--- configure.ac.orig	2011-12-09 04:33:14.000000000 -0600
+++ configure.ac	2021-07-08 21:16:21.000000000 -0500
@@ -20,7 +20,7 @@
 dnl List of tests
 AC_SUBST([TESTS], ["basic copymove props locks http"])
 
-NE_REQUIRE_VERSIONS([0], [25 26 27 28 29])
+NE_REQUIRE_VERSIONS([0], [25 26 27 28 29 30 31 32 33])
 NEON_WITHOUT_ZLIB
 NEON_WITHOUT_ACL
 NEON_TEST