Fix qsFilterReducer on pages not using it
Fix qsFilterReducer on pages not using it

Do not run if no namespace was determined by the patch matcher,
otherwise it tries to merge the query string into the top-level state.

OmeGak/indico,mvidalgarcia/indico,indico/indico,pferreir/indico,mic4ael/indico,ThiefMaster/indico,indico/indico,mic4ael/indico,pferreir/indico,ThiefMaster/indico,pferreir/indico,ThiefMaster/indico,ThiefMaster/indico,OmeGak/indico,indico/indico,DirkHoffmann/indico,mic4ael/indico,DirkHoffmann/indico,mvidalgarcia/indico,pferreir/indico,DirkHoffmann/indico,DirkHoffmann/indico,mic4ael/indico,OmeGak/indico,indico/indico,mvidalgarcia/indico,mvidalgarcia/indico,OmeGak/indico