make TimelineCache::timelines private

Signed-off-by: kernelkind <kernelkind@gmail.com>

crates/notedeck_columns/src/actionbar.rs

@@ -281,7 +281,7 @@ impl NewNotes {
     ) {
         let reversed = false;
 
-        let timeline = if let Some(profile) = timeline_cache.timelines.get_mut(&self.id) {
+        let timeline = if let Some(profile) = timeline_cache.get_mut(&self.id) {
             profile
         } else {
             error!("NewNotes: could not get timeline for key {}", self.id);