* Fix judger/log/
* fix(judger): Let judger work on ubuntu 20.04
Judger stops working since 9a6f16cf1d, this commit allows judger continue working.
* fix(web): update faq.php
Currently, if there is only one subtask, the bulitin judger automatically enters the ACM mode.
However, if the subtask has type "min", the judger should not do this. This commit fixes this bug.
For only web, there is no need to build checkers.
There are so many checkers that will slow down make speed.
Also for some situations, users can build checkers without runners.
Java 7 is now out of support. A large number of people use Java 8.
As the latest Java LTS version, now add support for Java 11.
Due to the policies from Oracle, SunJDK is replaced.