funding: attempt to send error back to caller within CancelPeerReservations

fundingmanager.go

@@ -603,6 +603,13 @@ func (f *fundingManager) CancelPeerReservations(nodePub [33]byte) {
 				"node=%x: %v", nodePub[:], err)
 		}
 
+		if resCtx.err != nil {
+			select {
+			case resCtx.err <- fmt.Errorf("peer disconnected"):
+			default:
+			}
+		}
+
 		delete(nodeReservations, pendingID)
 	}