Properly store deleted puzzle group collapse state.

As best as I can tell, this was a typo. Regular puzzle groups have their
state stored as long as there is no active search query. This makes
sense - as commit 2e09393 notes, it
would cause confusion when searching if we paid attention to collapse
state when showing search results. However, the deleted group behaves
the _opposite_ way - the state is _only_ persisted during searching. I
can't imagine why persisting the state in this case would be desirable,
but not during the no-search case. So this change makes everything
consistent.

See deathandmayhem#2278

imports/client/components/PuzzleListPage.tsx

@@ -479,7 +479,7 @@ const PuzzleListView = ({
               includeCount={false}
               canUpdate={canUpdate}
               suppressedTagIds={[]}
-              trackPersistentExpand={searchString !== ""}
+              trackPersistentExpand={searchString === ""}
             />
           )}
         </div>