qt: Use PeerTableSortProxy for sorting peer table

src/qt/peertablemodel.cpp

@@ -194,10 +194,7 @@ QVariant PeerTableModel::data(const QModelIndex &index, int role) const
         } // no default case, so the compiler can warn about missing cases
         assert(false);
     } else if (role == StatsRole) {
-        switch (index.column()) {
-        case NetNodeId: return QVariant::fromValue(rec);
-        default: return QVariant();
-        }
+        return QVariant::fromValue(rec);
     }
 
     return QVariant();