fix.修复基建allowExternal字段不生效及外部干员选择错误的问题

https://github.com/MistEO/MeoAssistantArknights/issues/288

src/MeoAssistant/InfrastConfiger.cpp

@@ -197,6 +197,7 @@ bool asst::InfrastConfiger::parse(const json::value& json)
                 }
                 group.optional.emplace_back(std::move(comb));
             }
+            group.allow_external = group_json.get("allowExternal", false);
             group_vec.emplace_back(std::move(group));
         }
         m_skills_groups.emplace(facility_name, std::move(group_vec));