修复错误的默认 ACL 规则,之前是:
{allow, {username, "^dashboard?"}, subscribe, ["$SYS/#"]}.
但执行正则表达式的匹配应该使用 {re, "^dashboard$"}:
{re, "^dashboard$"}
{allow, {username, {re, "^dashboard$"}}, subscribe, ["$SYS/#"]}.