Can't optimize sword weapons

[daftcoder]

Can't optimize sword weapons, e.g. on Keqing, Bennet, Xingqiu.

To Reproduce

1. Add new slot with Keqing
2. Click on Optimize Weapon
3. Console:

   genshinCalc.js:1 Uncaught TypeError: Cannot read property '0' of undefined
   at Weapon.GetSubStat (genshinCalc.js:1)
   at CharacterStats.calcModifiers (genshinCalc.js:1)
   at CharacterStats.getStats (genshinCalc.js:1)
   at DamageCalculator.Recalc (genshinCalc.js:1)
   at Optimizer._GetDPS (genshinCalc.js:1)
   at Optimizer.Optimize (genshinCalc.js:1)
   at HTMLButtonElement.OptimizeWeapon (genshinCalc.js:1)
   at HTMLButtonElement.dispatch (jquery.min.js:3)
   at HTMLButtonElement.q.handle (jquery.min.js:3)

Desktop:

• OS: WIndows 10
• Browser: Google Crome
• Version: 90.0.4430.85

[JenShin-368]

Fixed.