Fix off-by-one error in compacting delays

src/reskit/soundtrack/engines/echo.rs

@@ -405,7 +405,7 @@ pub fn compact_delays( events: Vec<EchoEvent> ) -> Result<Vec<EchoEvent>, Box<dy
                     let delay_type = *iter.next().ok_or( "internal error: empty event" )?;
 
                     if delay_type & 0xF0 == ESF_DELAY_SHORT {
-                        cumulative_delay += ( delay_type & 0x0F ) as u16;
+                        cumulative_delay += ( ( delay_type & 0x0F ) as u16 ) + 1;
                     } else if delay_type == ESF_DELAY_LONG {
                         cumulative_delay += ( *iter.next().ok_or( "internal error: expected delay byte" )? ) as u16;
                     }