Need 2.61 autoconf, not 2.63

M    configure.ac

Author: Patrick West

configure.ac

@@ -1,7 +1,7 @@
 # -*- Autoconf -*-
 # Process this file with autoconf to produce a configure script.
 
-AC_PREREQ(2.63)
+AC_PREREQ(2.61)
 AC_INIT(netcdf_handler, 3.10.2, opendap-tech@opendap.org)
 AC_CONFIG_AUX_DIR([conf])
 AC_CONFIG_MACRO_DIR([conf])