unitframes: adjust custom portrait code

* align indentation to codestyle
* remove option to enable custom size
* remove obsolete translations

env/translations_koKR.lua

@@ -525,7 +525,6 @@ pfUI_translation["koKR"] = {
   ["Please enter a name of a character who should receive your whispers:"] = nil,
   ["Portrait Alpha"] = "초상화 투명도",
   ["Portrait Position"] = "초상화 위치",
-  ["Enable Custom Portrait Size"] = "사용자 정의 세로 크기 활성화",
   ["Portrait Height"] = "세로 높이",
   ["Portrait Width"] = "세로 너비",
   ["Powerbar"] = nil,