Fix: panic when parsing duration with one digit hours

src/parser.rs

···
             }
             Ok(XmlEvent::Characters(duration_str)) => {
                 if in_duration {
-                    let duration_str = duration_str.replace(':', "");
                     duration = Some(duration_str);
                 }
             }
···
     }
 
     let duration = duration.ok_or_else(|| anyhow!("Invalid response from device"))?;
-    let hours = duration[0..2].parse::<u32>()?;
-    let minutes = duration[2..4].parse::<u32>()?;
-    let seconds = duration[4..6].parse::<u32>()?;
+    let mut duration_iter = duration.split(":");
+    let hours = duration_iter.next().unwrap_or("0").parse::<u32>()?;
+    let minutes = duration_iter.next().unwrap_or("0").parse::<u32>()?;
+    let seconds = duration_iter.next().unwrap_or("0").parse::<u32>()?;
     Ok(hours * 3600 + minutes * 60 + seconds)
 }