Using magnolia.utf8.enabled=true a NPE occurs on UnicodeNormalizationFilter.

With MAGNOLIA-3204 the method resetAggregationState has been modified and now it set these aggregationState properties to:
this.originalURI=null;
this.originalURL=null;
this.originalBrowserURI=null;
this.originalBrowserURL=null;
this.currentURI = null;

cannot be passed a null value to UnicodeNormalizer.normalizeNFC(null), this cause NPE.

The UnicodeNormaliazioneFilter has to normalize originalURI/URL, to overwrite these properties it needs to reset it, otherwise IllegalStateException could occurs.

patch Included, if ok I can commit it.