Change c_user_session to varchar and update constraints

Scripts/mysql-utf8mb4.sql

@@ -166,11 +166,11 @@ CREATE TABLE sogo_admin (
 ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 ROW_FORMAT=DYNAMIC;
 
 CREATE TABLE sogo_opend_id (
-	c_user_session              text NOT NULL,
+	c_user_session              varchar(255) NOT NULL,
 	c_old_session              text DEFAULT '',
 	c_session_started           int(11)       NOT NULL,
 	c_refresh_token             text DEFAULT '',
-	c_access_token_expires_in    int(11)       DEFAULT '',
+	c_access_token_expires_in    int(11)       NOT NULL,
 	c_refresh_token_expires_in  int(11)       DEFAULT NULL,
 	PRIMARY KEY (c_user_session)
 ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 ROW_FORMAT=DYNAMIC;