core: fix a problem where a search could result in illegal SQL

This could happen if a query without any search arguments was used and a clause was added to restrict results for certain users.

src/support/z_search.erl

@@ -494,8 +494,7 @@ publish_check(Alias, #search_sql{extra=Extra}) ->
             [];
         false ->
             [
-                " and "
-                , Alias, ".is_published = true and "
+                  Alias, ".is_published = true and "
                 , Alias, ".publication_start <= now() and "
                 , Alias, ".publication_end >= now()"
             ]