Ask for the subscription once when saving a feed's settings (#163)

patch_feed asked whether you subscribe, then asked again for the subscription, with a fallback for
none that could never run, since it only got there when there was one. One if-let does both.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

src/web.rs

@@ -1574,12 +1574,7 @@ async fn patch_feed(
     }
     // What one person wants -- which items, whether to fetch them, how many at a time --
     // is theirs. It goes on their subscription and nobody else sees the change.
-    if state.ctx.db.subscription(user.id, &id).await?.is_some() {
-        let mut mine = state
-            .ctx
-            .db
-            .subscription(user.id, &id).await?
-            .unwrap_or_else(|| crate::db::Sub { feed_id: id.clone(), ..Default::default() });
+    if let Some(mut mine) = state.ctx.db.subscription(user.id, &id).await? {
         let mut touched = false;
         if let Some(v) = body.keywords.clone() {
             mine.keywords = Some(v.into_iter().filter(|k| !k.trim().is_empty()).collect());