$NetBSD$

Improve test portability to non-bash shells.

--- configure.orig	2019-06-03 14:10:18.291079910 +0000
+++ configure
@@ -63946,7 +63946,7 @@ _ACEOF
 
 else
 
-        if test "x$enable_nls" == "xcheck"
+        if test "x$enable_nls" = "xcheck"
 	then
 	  enable_nls=no
 	else
@@ -63972,7 +63972,7 @@ _ACEOF
  enable_nls=yes
 else
 
-      if test "x$enable_nls" == "xcheck"
+      if test "x$enable_nls" = "xcheck"
       then
         enable_nls=no
       else