if `rbac` is from config then `can` may be undefined there too
if `rbac` is from config then `can` may be undefined there too

fix 5aed49a28f5b2ed2f263526381437ee5a5b734f2

Signed-off-by: Oleg Verych <a5ce24b76737c0ca6b8faa55c4f938064a1695cf@gmail.com>

suprojs/supromongod,suprojs/supromongod,suprojs/supromongod