client: fix NewOptions with CallOptions filling

Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>

client/options.go

@@ -160,6 +160,7 @@ func NewOptions(opts ...Option) Options {
 		ContentType: DefaultContentType,
 		Codecs:      make(map[string]codec.Codec),
 		CallOptions: CallOptions{
+			Context:        context.Background(),
 			Backoff:        DefaultBackoff,
 			Retry:          DefaultRetry,
 			Retries:        DefaultRetries,