$NetBSD$

"test ==" portability fix.

--- configure.orig	2009-09-05 22:53:17.000000000 +0400
+++ configure	2009-09-05 23:01:05.000000000 +0400
@@ -10040,7 +10040,7 @@
 #define HAVE_NETCDF 1
 _ACEOF
 
-	if test "$USE_SYSTEM_NETCDF" == no; then
+	if test "$USE_SYSTEM_NETCDF" = no; then
 		USE_SYSTEM_NETCDF="X"
 	else
 		echo "$as_me:$LINENO: checking for main in -lnetcdf" >&5
