Fix category CSS
Fix category CSS

Before, when the category is closed by default, the active CSS class wasn't applied. Thus breaking the shortcuts for navigation.
Now it works the way it is supposed.

superboum/FreshRSS,Dolomich/FreshRSS,Alkarex/FreshRSS,Alkarex/FreshRSS,superboum/FreshRSS,aledeg/FreshRSS,aledeg/FreshRSS,romibi/FreshRSS,romibi/FreshRSS,aledeg/FreshRSS,aledeg/FreshRSS,Dolomich/FreshRSS,Alkarex/FreshRSS,FreshRSS/FreshRSS,FreshRSS/FreshRSS,plopoyop/FreshRSS,Alkarex/FreshRSS,marienfressinaud/FreshRSS,FreshRSS/FreshRSS,superboum/FreshRSS,Dolomich/FreshRSS,plopoyop/FreshRSS,asmundg/FreshRSS,samuelstein/FreshRSS,samuelstein/FreshRSS,samuelstein/FreshRSS,marienfressinaud/FreshRSS,asmundg/FreshRSS,marienfressinaud/FreshRSS,romibi/FreshRSS,marienfressinaud/FreshRSS,asmundg/FreshRSS,FreshRSS/FreshRSS,romibi/FreshRSS