webmail: updated changelog

webmail/debian/changelog

+symbiosis-webmail (2014:1112) stable; urgency=medium
+
+  * Remove accidental config clobbering
+
+ -- James Carter <jcarter@bytemark.co.uk>  Wed, 19 Aug 2015 16:10:02 +0100
+
 symbiosis-webmail (2014:1111) stable; urgency=medium
 
   * Fix up symbiosis-webmail-roundcube postinst to act more like our