Both MultiCastBar.lua and Options/MultiCastBar.lua hard-coded a class-mask
gate of SHAMAN|HERO, which doesn't know about CoA custom classes. As a
result, Witchdoctor (and any other CoA class the engine produces a totem
bar for) never had Bartender's wrapper module register, leaving the totem
bar un-skinned / un-configurable.
Keep the original mask check as the fast path, but fall through and load
the module when MultiCastActionBarFrame already exists — the engine only
creates that frame for classes that actually use the totem bar, so it's a
reliable class-agnostic test.
florian.berthold