state: Properly propagate errors when persisting state

src/state.rs

@@ -59,14 +59,14 @@ impl FeedReaderStateDb {
         &self,
         uri: &str,
         dt: DateTime<Utc>
-        ) -> () {
+        ) -> Result<(), Box<dyn Error>> {
 
         {
             debug!("Updating feed reader state");
             self.lock_state().insert(uri.into(), dt.timestamp().into());
         }
 
-        self.persist().await.unwrap();
+        self.persist().await
     }
 
     #[tracing::instrument(ret, level="debug")]