The hub plugin uses jsonschema, so it must explicitly depend on
it. The dependency is installed "by hand" in the container since
by default, the plugin is not installed via the RPM, but copied
from the source repository and thus all dependencies must be
present already.
Use the requests python package, which is more convenient to use,
and also supports sessions, where global options, like TLS certs
can be set.
Adapt the container and the spec file to install and require
the python package.
