plugins: imap-filter-sieve: cmd-filter-sieve - Avoid using...

plugins: imap-filter-sieve: cmd-filter-sieve - Avoid using imap_arg_as_nstring() in cmd_filter_sieve_script_parse_value_arg()

The argument can only be a quoted string here, so imap_arg_as_string() will suffice.

src/plugins/imap-filter-sieve/cmd-filter-sieve.c

@@ -267,7 +267,7 @@ cmd_filter_sieve_script_parse_value_arg(struct imap_filter_context *ctx)
 		/* We have the value already */
 		if (ctx->failed)
 			return 1;
-		value = imap_arg_as_nstring(&args[0]);
+		value = imap_arg_as_astring(&args[0]);
 		input = i_stream_create_from_data(value, strlen(value));
 		cmd_filter_sieve_compile_input(ctx, input);
 		i_stream_unref(&input);