Prevent snowball throw if player hasn't selected a class

Added

src/main/java/com/alttd/ctf/events/SnowballEvent.java

@@ -89,6 +89,7 @@ public class SnowballEvent implements Listener {
         handleSnowballThrown(event, (shooter, shooterTeamPlayer, snowball) -> {
             GameClass shooterClass = shooterTeamPlayer.getGameClass();
             if (shooterClass == null) {
+                shooter.sendRichMessage("<red>You appear to not have selected a class, please do so by going to spawn and using /ctf selectclass</red>");
                 event.setCancelled(true);
                 return;
             }