fix: use storage topic if topic is not available on connection to pre…

…vent errors (header topic is missing on ros noetic rosbags)

src/record_types/connection.rs

@@ -85,7 +85,7 @@ impl<'a> RecordGen<'a> for Connection<'a> {
             }
         }
 
-        let topic = topic.ok_or(Error::InvalidHeader)?;
+        let topic = topic.unwrap_or(storage_topic);
         let tp = tp.ok_or(Error::InvalidHeader)?;
         let md5sum = md5sum.ok_or(Error::InvalidHeader)?;
         let message_definition = message_definition.ok_or(Error::InvalidHeader)?;