Another little fix on hunter Disengage - stop it from being usable when rooted

--HG--
branch : trunk

src/game/Spell.cpp

@@ -5199,6 +5199,8 @@ SpellCastResult Spell::CheckCast(bool strict)
                 if (m_spellInfo->Id == 781)
                     if (!m_caster->isInCombat())
                         return SPELL_FAILED_CANT_DO_THAT_RIGHT_NOW;
+                    if (m_caster->hasUnitState(UNIT_STAT_ROOT))
+                        return SPELL_FAILED_ROOTED;
                 break;
             }
             default:break;