LU-7372 tests: re-enable replay-dual test_26

LU-7372 tests: re-enable replay-dual test_26

Re-enable test_26 since it was just the unfortunate victim of
either test_24 or test_25 causing MDS unmount to hang.

Test-Parameters: trivial testgroup=review-dne-part-2
Test-Parameters: testgroup=review-dne-part-2
Test-Parameters: testgroup=review-dne-part-2
Test-Parameters: testgroup=review-dne-part-2
Signed-off-by: Andreas Dilger <adilger@whamcloud.com>
Change-Id: Ib944028e798488c425501f0c48bf812fc13ebbe5
Reviewed-on: https://review.whamcloud.com/43982
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: James Nunez <jnunez@whamcloud.com>
Reviewed-by: Elena Gryaznova <elena.gryaznova@hpe.com>
Reviewed-by: Vikentsi Lapa <vlapa@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>