Tooltips for enchantments with invalid effects cause crashes

This mod was probably made in MWEdit and not TESCS and has invalid magic effects assigned to some enchantments (Ten Pace Boots, Ward of Araynis, Telvanni helmets) which cause these items' tooltips to crash the game due to assuming the effect is never invalid instead of e.g. throwing an exception. Still, instead of simply throwing exceptions the invalid effects should be dropped from the affected items like what's done for spells before tooltip code hits itself in confusion.