Dropping ical_tzid_prefix makes Open-Xchange like our timezone

libical-1.0-tzid.patch

--- libical-1.0/src/libical/icaltz-util.c.orig	2013-04-14 13:24:42.000000000 -0400
+++ libical-1.0/src/libical/icaltz-util.c	2015-05-11 23:21:20.632759999 -0400
@@ -349,11 +349,8 @@
 	tz_comp = icalcomponent_new (ICAL_VTIMEZONE_COMPONENT);
 
 	/* Add tzid property */
-	tzid = (char *) malloc (strlen (ical_tzid_prefix) + strlen (location) + 8);
-	sprintf (tzid, "%sTzfile/%s", ical_tzid_prefix, location);
-	icalprop = icalproperty_new_tzid (tzid);
+	icalprop = icalproperty_new_tzid (location);
 	icalcomponent_add_property (tz_comp, icalprop);
-	free (tzid);
 
 	icalprop = icalproperty_new_x (location);
 	icalproperty_set_x_name (icalprop, "X-LIC-LOCATION");