Fixing NPE in WindowBuilder

src/main/lombok/org/leumasjaffe/charsheet/view/magic/SelectPreparedSpellsPanel.java

@@ -49,7 +49,7 @@ class SelectPreparedSpellsPanel extends JPanel {
 
 		@Override
 		public int getRowCount() {
-			return data.length;
+			return data == null ? 0 : data.length;
 		}
 
 		@Override