f - make OfferBuilder::features test-only

Author: jkczyz

lightning/src/offers/offer.rs

@@ -120,6 +120,7 @@ impl OfferBuilder {
 	/// Sets the features for the offer.
 	///
 	/// Successive calls to this method will override the previous setting.
+	#[cfg(test)]
 	pub fn features(mut self, features: OfferFeatures) -> Self {
 		self.offer.features = Some(features);
 		self