Ignore "extra" when counting page references.

This is not relevant to page counts, it points to a particular anchor
(if anything), which means that for backlinks calculations this field
should be omitted.

Author: emmiegit

deepwell/src/services/link/service.rs

@@ -471,6 +471,7 @@ async fn count_connections(
     PageRef {
         site: site_slug,
         page: page_slug,
+        extra: _,
     }: &PageRef,
     connection_type: ConnectionType,
     connections: &mut HashMap<(i64, ConnectionType), i32>,