Fix include task using a potentially undefined variable

test/integration/roles/test_file/tasks/main.yml

@@ -137,7 +137,7 @@
 
 - name: decide to include or not include selinux tests
   include: selinux_tests.yml
-  when: selinux_installed.stdout != "" and selinux_enabled.stdout != "Disabled"
+  when: selinux_installed is defined and selinux_installed.stdout != "" and selinux_enabled.stdout != "Disabled"
 
 - name: remote directory foobar
   file: path={{output_dir}}/foobar state=absent