Functional tests for restricted shell.
Tested build 2005 on Fedora 33: Feature: Restricted shell - user shell ✓ Scenario: ThinLinc client ✓ Scenario: SSH Feature: Restricted shell - ForceCommand ✓ Scenario: ThinLinc client ✓ Scenario: SSH
Tested build 2250 on Fedora 34: Feature: Restricted shell - user shell ✓ Scenario: ThinLinc client ✓ Scenario: SSH Feature: Restricted shell - ForceCommand ✓ Scenario: ThinLinc client ✓ Scenario: SSH