force symlink creation for enable_web_vhost

- add '-f' parameter to ln invocation
- add changelog entry

docs/changelog.rst

@@ -1,6 +1,9 @@
 Changelog
 =========
 
+* :bugfix:`-` force symlink creation for enable_web_vhost task to make it
+  idempotent
+
 * :release:`0.1.0 <2015-01-27>`
 * :feature:`-` add tasks to setup and delete per user PHP5 FPM pool
   configurations

gvaweb/webtasks/tasks.py

@@ -137,7 +137,7 @@ def enable_web_vhost(sitename):
     """
     try:
         subprocess.check_output([
-            SUDO_CMD, LN_CMD, '-s',
+            SUDO_CMD, LN_CMD, '-s', '-f',
             _build_vhost_config_path(sitename),
             _build_enabled_vhost_path(sitename)],
             stderr=subprocess.STDOUT)