store is_convert in Beatmap itself

src/catch/convert.rs

@@ -38,6 +38,7 @@ pub fn try_convert(map: &mut Beatmap) -> ConvertStatus {
     match map.mode {
         GameMode::Osu => {
             map.mode = GameMode::Catch;
+            map.is_convert = true;
 
             ConvertStatus::Conversion
         }

src/catch/difficulty/mod.rs

@@ -53,7 +53,7 @@ impl CatchDifficultySetup {
 
         let attrs = CatchDifficultyAttributes {
             ar: map_attrs.ar,
-            is_convert: converted.is_convert,
+            is_convert: converted.map.is_convert,
             ..Default::default()
         };