Fix : creating user from member was failing due to column size difference

htdocs/install/mysql/migration/3.9.0-4.0.0.sql

@@ -544,4 +544,6 @@ INSERT INTO llx_c_forme_juridique (fk_pays, code, libelle, active) VALUES (178,
 -- VMYSQL4.1 ALTER TABLE llx_establishment CHANGE COLUMN fk_user_mod fk_user_mod integer NULL;
 -- VPGSQL8.2 ALTER TABLE llx_establishment ALTER COLUMN fk_user_mod DROP NOT NULL;
 
-ALTER TABLE llx_multicurrency_rate ADD COLUMN entity integer DEFAULT 1;
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+ALTER TABLE llx_multicurrency_rate ADD COLUMN entity integer DEFAULT 1;
+
+ALTER TABLE llx_user MODIFY COLUMN login varchar(50);
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