Correct changed_when statement.

tasks/openbsd_bootstrap.yml

@@ -9,7 +9,7 @@
 - name: Symlink python
   raw: ln -s /usr/local/bin/python2.7 /usr/bin/python
   register: symlink_python
-  changed_when: not 'File exists' in symlink_python.stderr
+  changed_when: not 'File exists' in symlink_python.stdout_lines[0]
   failed_when: symlink_python|failed and not 'File exists' in symlink_python.stdout_lines[0]
 
 - name: Gather facts