Fix error on attempting to claim a 19th character-specific macro

[spiralofhope]

TL;DR the SDM window understand there are 18/18, so "claim" should just be greyed out..

This was discovered during exploration for #21

---

• new character
• disable addons
• /macro > "<name> Specific Macros"
• /sdm
• move the SDM window next to the macro window
• in sdm: New
  • Button Macro
  • Character-specific
  • Name: OVERWRITE_TEST
• in the OVERWRITE_TEST macro, edit its text to be:

TESTING

in the /macro list..

• switch to the "General Macros" tab, and then the "<name> Specific Macros" tab
• (confirm the SDM macro appears. It cannot be clicked on)
• New >
  • name it "1"
  • (don't bother choosing an icon)
  • (leave the content empty)
• in the SDM list, for the OVERWRITE_TEST macro, click "Disown"
• in the /macro list, click the macro you called 1
• (confirm the SDM macro disappears from the /macro list.
• in the SDM list, for the OVERWRITE_TEST macro, click "Claim"
• in the /macro list, click the macro you called 1
• (confirm the SDM macro re-appears in the /macro list.

Continue creating macros (even with the same name) until 17 are created, the entire macros list is full.

• in the SDM list, for the OVERWRITE_TEST macro, click "Disown"
• in the /macro list, click the macro you called 1
• (confirm the SDM macro disappears from the /macro list.

Create one additional macro in the /macro list, so that it's full.

• in the SDM list, for the OVERWRITE_TEST macro, click "Claim"

Click to expand

``` 1x [string "local macroIndex = sdm_GetMacroIndex(471)..."]:6: CreateMacro() failed, already have 120 macros [C]: in function `CreateMacro' [string "local macroIndex = sdm_GetMacroIndex(471)..."]:6: in main chunk [C]: in function `RunScript' ...faceSuperDuperMacro\SuperDuperMacro_Core.lua:406: in function `sdm_DoOrQueue' ...faceSuperDuperMacro\SuperDuperMacro_Core.lua:167: in function `sdm_MakeBlizzardMacro' ...faceSuperDuperMacro\SuperDuperMacro_Core.lua:277: in function `sdm_SetUpMacro' SuperDuperMacro\SuperDuperMacro_Interface.lua:93: in function

Locals:
(*temporary) = "OVERWRITE_TEST"
(*temporary) = "INV_MISC_QUESTIONMARK"
(*temporary) = "#sdm%&

Enter macro text here."

(*temporary) = true
(*temporary) = 1

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