Add “20 Sous = 1 Libra” to the Libra currency for Catalonia [Risolto]

The Libra currency of Catalonia was previously changed, but the end result didn't actually connect the listed denominations to the base unit of the currency. 20 Sous = 1 Libra should be added to the currency definition.

Previous discussion on changing the currency: https://en.numista.com/forum/topic88154.html

Current currency definition: 4 Pugesa = 2 Obolo = 1 Dinero · 6 Dinero = 3 Ardit = 1 Seiseno · 2 Sous = 1 Croat = 1 Real · 15 Sous = 1 Florin · 24 Sous = 1 gold Principado · 33 Sous = 1 Trentin

Fixed, thank you. :)

The Carolingian pound (libra) was the base of the Catalonian and others European monetary systems, but in this case never was a physical coin neither a unit of count. But as we have the values in Numista related to the pound, I think it is right to show this relationship.