Update path to sievec

Index: sid/pysieved.ini
===================================================================
--- sid.orig/pysieved.ini	2012-04-09 16:19:06.904001000 +0100
+++ sid/pysieved.ini	2012-04-09 16:34:06.957175537 +0100
@@ -82,7 +82,7 @@
 #master = /var/run/dovecot/auth-master
 
 # Path to sievec
-sievec = /usr/lib/dovecot/sievec
+sievec = /usr/bin/sievec
 
 # Where in user directory to store scripts
 scripts = .pysieved