cap size of remote filter limits

I noticed the responses are a bit slow without this. Local query limits
are not capped.

Fixes: https://github.com/damus-io/notedeck/issues/98
Changelog-Changed: Restrict remote filter sizes to 250 (for now)
Signed-off-by: William Casarin <jb55@jb55.com>

src/app.rs

@@ -97,6 +97,12 @@ fn send_initial_filters(damus: &mut Damus, relay_url: &str) {
                 let mut filter = timeline.filter.clone();
                 for f in &mut filter {
                     since_optimize_filter(f, timeline.notes(ViewFilter::NotesAndReplies));
+
+                    // limit the size of remote filters
+                    let lim = f.limit.unwrap_or(100);
+                    if lim > 150 {
+                        f.limit = Some(150);
+                    }
                 }
                 relay.subscribe(format!("initial{}", c), filter);
                 c += 1;