Fix spellcast adjustment not working

[GuardianDll]

Summary

None

Purpose of change

Spellcast adjustment didn't apply it's effect

Describe the solution

Tweak code so it actually works

Testing

  {
    "type": "effect_on_condition",
    "id": "EOC_metamagic_extend",
    "eoc_type": "EVENT",
    "required_event": "opens_spellbook",
    "effect": [
      { "math": [ "u_spellcasting_adjustment('duration', 'flag_blacklist': 'PERMANENT_ALL_LEVELS' )", "=", "10.0" ] },
      { "math": [ "u_spellcasting_adjustment('cost', 'flag_blacklist': 'PERMANENT_ALL_LEVELS' )", "=", "0.5" ] }
    ]
  },

with this eoc, all spells always have 10 times bigger duration than before
(i lost the screenshots with in game tests :( )