Refactor sliding window selector. (fixes #170)

Refactor list filtering.

Signed-off-by: Jason Volk <jason@zemos.net>

src/service/rooms/read_receipt/data.rs

@@ -97,7 +97,7 @@ impl Data {
 		self.readreceiptid_readreceipt
 			.rev_keys_prefix(&key)
 			.ignore_err()
-			.ready_take_while(|(_, c, _): &Key<'_>| since.is_none_or(|since| since.gt(&c)))
+			.ready_take_while(|(_, c, _): &Key<'_>| since.is_none_or(|since| since.gt(c)))
 			.ready_filter(|(_, _, u): &Key<'_>| user_id.as_ref().is_none_or(is_equal_to!(u)))
 			.map(|(_, c, _): Key<'_>| c)
 			.boxed()