Remove 'ignore missing territories block'

This block does not do anything.. We later check if all map
territories are in the keyset that comes from a save game. If
we have extra territories in the save game, removing them is
not going to have an effect when we check that all territories
in the map are in the save game.

IE:

The following contains check will be no different if we decrease the size
of the 'keys' set:
```
      if (!keys.contains(terr.getName())) {
```

game-core/src/main/java/games/strategy/triplea/ui/mapdata/MapData.java

@@ -536,15 +536,7 @@ public void verify(final GameData data) {
   private static void verifyKeys(
       final GameData data, final Set<String> keys, final String dataTypeForErrorMessage) {
     final StringBuilder errors = new StringBuilder();
-    final Iterator<String> iter = keys.iterator();
-    while (iter.hasNext()) {
-      final String name = iter.next();
-      final Territory terr = data.getMap().getTerritory(name);
-      // allow loading saved games with missing territories; just ignore them
-      if (terr == null) {
-        iter.remove();
-      }
-    }
+
     for (final Territory terr : data.getMap().getTerritories()) {
       if (!keys.contains(terr.getName())) {
         errors