Fix the case statement

If do not set the case will lead to this lint warning of
"case statement without a default case"

Change-Id: Ic09ea73251cb8e86fd00aa63c46730ee6ef28a4c

spec/acceptance/ironic_wsgi_apache_spec.rb

@@ -80,6 +80,9 @@ describe 'basic ironic' do
             db_connection   => 'mysql+pymysql://ironic-inspector:a_big_secret@127.0.0.1/ironic-inspector?charset=utf8',
           }
         }
+        default: {
+          fail("Unsupported osfamily (${::osfamily})")
+        }
       }
       EOS