f fix docs

Author: TheBlueMatt

lightning/src/ln/channel.rs

@@ -5502,7 +5502,8 @@ impl<Signer: Sign> Channel<Signer> {
 	///   we may not yet have sent the previous commitment update messages and will need to
 	///   regenerate them.
 	///
-	/// You MUST call send_commitment prior to calling any other methods on this Channel!
+	/// You MUST call send_commitment prior to calling any other methods on this Channel if
+	/// `force_holding_cell` is false.
 	///
 	/// If an Err is returned, it's a ChannelError::Ignore!
 	fn send_htlc<L: Deref>(&mut self, amount_msat: u64, payment_hash: PaymentHash, cltv_expiry: u32, source: HTLCSource,