update integration test

Author: schaefi

build-tests/x86/tumbleweed/test-image-disk/appliance.kiwi

@@ -56,6 +56,7 @@
     </preferences>
     <users>
         <user password="$1$wYJUgpM5$RXMMeASDc035eX.NbYWFl0" home="/root" name="root" groups="root"/>
+        <user password="$1$wYJUgpM5$RXMMeASDc035eX.NbYWFl0" home="/home/test-user" name="test-user" groups="users"/>
     </users>
     <repository type="rpm-md">
         <source path="obsrepositories:/"/>