Fix invalid mix function overload

servers/visual/shader_language.cpp

@@ -1611,7 +1611,7 @@ const ShaderLanguage::BuiltinFuncDef ShaderLanguage::builtin_func_defs[] = {
 	{ "mix", TYPE_VEC3, { TYPE_VEC3, TYPE_VEC3, TYPE_VEC3, TYPE_VOID } },
 	{ "mix", TYPE_VEC4, { TYPE_VEC4, TYPE_VEC4, TYPE_FLOAT, TYPE_VOID } },
 	{ "mix", TYPE_VEC4, { TYPE_VEC4, TYPE_VEC4, TYPE_BOOL, TYPE_VOID } },
-	{ "mix", TYPE_VEC4, { TYPE_VEC4, TYPE_VEC4, TYPE_BVEC3, TYPE_VOID } },
+	{ "mix", TYPE_VEC4, { TYPE_VEC4, TYPE_VEC4, TYPE_BVEC4, TYPE_VOID } },
 	{ "mix", TYPE_VEC4, { TYPE_VEC4, TYPE_VEC4, TYPE_VEC4, TYPE_VOID } },
 
 	{ "step", TYPE_FLOAT, { TYPE_FLOAT, TYPE_FLOAT, TYPE_VOID } },