Fix typo in playbooks/yaml2ical/post.yaml

Fix:
  rsync: mkdir "/src/yaml2ical/calendars" failed: No such file or directory (2)

It's /srv, not /src as a few lines above.

Change-Id: I86326fa7de68a0db7e6893e8ab291ba33fe6018d

playbooks/yaml2ical/post.yaml

@@ -37,4 +37,4 @@
     - name: Copy calendars
       synchronize:
         src: "{{ zuul.executor.work_root }}/yaml2ical/calendars/"
-        dest: "/src/yaml2ical/calendars"
+        dest: "/srv/yaml2ical/calendars"