Fix: [ bug #1765 ] Unable to create a contract

htdocs/install/mysql/tables/llx_contrat.sql

@@ -23,6 +23,7 @@ create table llx_contrat
   rowid						integer AUTO_INCREMENT PRIMARY KEY,
   ref						varchar(30),		            -- contrat reference
   ref_supplier				varchar(30),		            -- suplier contract ref
+  ref_ext				varchar(30),		            -- external contract ref
   entity					integer DEFAULT 1 NOT NULL,	-- multi company id
   tms						timestamp,
   datec						datetime,                   -- creation date