LU-15007 tests: quota enable cmd fix

LU-15007 tests: quota enable cmd fix

the tunable should be osd-*.*.quota_slave.enabled
not osd-*.*.quota_slave.enable.

Fixes: b9c359a70d ("LU-7004 tests: move from lctl conf_param to lctl set_param -P")

Test-Parameters: trivial testlist=ost-pools,sanity-quota
HPE-bug-id: LUS-10413
Signed-off-by: Alexander Zarochentsev <alexander.zarochentsev@hpe.com>
Change-Id: I321436520ab48eff4bcc93611a0ada68fa33205e
Reviewed-on: https://review.whamcloud.com/44919
Tested-by: jenkins <devops@whamcloud.com>
Reviewed-by: Andrew Perepechko <andrew.perepechko@hpe.com>
Reviewed-by: Artem Blagodarenko <artem.blagodarenko@hpe.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>