build-docker-images: stx-nova: Unable to clone `spice-html5` (504)

[Luan Nunes Utimura]

Brief Description
-----------------
It has been observed that, when building the `stx-nova` container image, the `build-docker-images` script is failing due to a *gateway timeout* when cloning spice-html5's repository.

Severity
--------
Critical.

The `build-docker-images` step fails (and so does the `stx-openstack` build).

Steps to Reproduce
------------------
Attempt to build `stx-nova` with `build-docker-images.sh`.

Expected Behavior
------------------
The build finishes successfully.

Actual Behavior
----------------
The build fails.

Reproducibility
---------------
Reproducible.

System Configuration
--------------------
N/A.

Branch/Pull Time/Commit
-----------------------
StarlingX (master)

Last Pass
---------
N/A.

Timestamp/Logs
--------------
```
06:31:54 + git clone -b spice-html5-0.1.6 --depth 1 https://gitlab.freedesktop.org/spice/spice-html5 /usr/share/spice-html5
06:31:54 Cloning into '/usr/share/spice-html5'...
06:33:31 fatal: unable to access 'https://gitlab.freedesktop.org/spice/spice-html5/': The requested URL returned error: 504
```

Test Activity
-------------
Developer Testing.

Workaround
----------
N/A.

[Lucas de Ataides Barreto (ldeataid)]

The entire freedesktop's Gitlab seems to be unresponsive: https://gitlab.freedesktop.org

[Luan Nunes Utimura (lutimura)]

As discussed with the community in the "StarlingX Build" chat (Matrix), this failure was caused by an intermittency during the migration of GitLab servers. Therefore, I'm closing it as "invalid".