Update to latest mainline Proot

[Tuupertunut]

The latest mainline Proot (https://github.com/proot-me/proot) seems to run Ubuntu much better than the custom Udocker-proot currently bundled with Udocker.

Before:
With the bundled Proot running Ubuntu 22.04 in --execmode=P1, I get the following errors when running apt update:

root@machine:~# apt update
Reading package lists... Done
E: Method gave invalid 400 URI Failure message: Could not switch saved set-user-ID
E: Method gave invalid 400 URI Failure message: Could not switch saved set-user-ID
E: Method http has died unexpectedly!
E: Sub-process http returned an error code (112)

After:
With mainline Proot starting from commit proot-me/proot@a0dc181, running Ubuntu 22.04 in --execmode=P1, I get no errors. Ubuntu runs as it should. apt update works, as well as installing packages. Even complex packages such as systemd are easily installed.

(Note: the latest Proot release 5.3.1 causes different errors, as explained here: proot-me/proot#338. It is only after that pull request that Ubuntu starts to run without issues.)

[jorge-lip]

This is was implemented in the latest versions of udocker.