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
> Really not work properly because it can cause bug a distance of about 4 yards, the Dummy effect is applied, but the ActiveObject is not applied, so never disappears.
well, caused by nearby target using spellrange instead of effectradius