Description of problem:
Using "hosted-engine --deploy --config-append=<whatever>" fails when a language is set. It fails when trying to check for space for the HE setup:

[ INFO  ] TASK [ovirt.hosted_engine_setup : Ensure we have enough space to extract the appliance]
[ ERROR ] fatal: [localhost]: FAILED! => {
             "assertion": "local_vm_dir_space_out.stdout_lines[0]|int * 1024 > appliance_size.stdout_lines[0]|int * 1.1", 
             "changed": false, 
             "evaluated_to": false, 
             "msg": "/var/tmp doesn't provide enough free space to extract the engine appliance: 0.0 Mb are available while 2892.13867188 Mb are required.\n"
         }

This is due to 
/usr/share/ansible/roles/ovirt.hosted_engine_setup/tasks/bootstrap_local_vm/02_create_local_vm.yml
      - name: Check available space on local VM directory
        shell: df -k --output=avail "{{ he_local_vm_dir_path }}" | grep -v Avail

which checks for "Avail" which is only there if LANGUAGE is english or set to "C".


How reproducible:
Always with LANGUAGE set to non english.

Steps to Reproduce:
1. export LANGUAGE=de_DE.UTF-8
2. hosted-engine --deploy --config-append=<whatever>


Actual results:
Deployment fails with erraneous message about to enough space in /var/tmp.

Expected results:
Deployment succeeds.

Additional info:
To avoid you can use
LANGUAGE=C hosted-engine --deploy --config-append=<whatever>
which should be added to the documentation!