Create table if not exists

pgsql-schema.sql

@@ -8,13 +8,10 @@
 --        - type 'integer' is used (we have to check for overflows ..)
 --        - type 'datetime' has been replaced by 'timestamp'
 
-
-DROP TABLE IF EXISTS ulog2_ct CASCADE;
-
 -- 
 -- conntrack
 -- 
-CREATE TABLE ulog2_ct (
+CREATE TABLE IF NOT EXISTS ulog2_ct (
   ct_id bigint PRIMARY KEY UNIQUE NOT NULL,
   oob_family smallint default NULL,
   orig_ip_saddr_str inet default NULL,