Scripts/Quests: Fix Red Snapper - Very Tasty! GOb

Fix 'School of Red Snapper' now disappear correctly when using 'Draenei Fishing Net', the bug is caused because the GameObject is SpellFocus type.

Fix: #1673
according to my github notifications, you broke the conditions?
```sql
UPDATE `conditions` SET `ScriptName`='condition_q9452_cast_net' WHERE `SourceTypeOrReferenceId`=13 AND `SourceEntry`=29866 AND `ConditionTypeOrReference`=31 AND `ConditionValue2`=181616;
```