Issues with bug740489.sh

There's a couple of minor issues with the bug740489.sh test:

- it should pass --no-version-check to innobackupex to skip version checks as other tests do;

- it should copy InnoDB configuration from the default my.cnf created by the test framework. The reason is that if a host where the test is being executed has global my.cnf in /etc/, --defaults-extra-file will read configuration from that file as well (which conforms to the specification). However, if InnoDB values in /etc/my.cnf do not match those in the default my.cnf created by the test suite, the test will fail.