LU-15053 tests: reset quota if ENABLE_QUOTA=1

Quota limits set in setup_quota() with ENABLE_QUOTA=1
should be cleaned up in the end to avoid failures in
the next sessions

Test-Parameters: testlist=sanity-quota env=ENABLE_QUOTA=yes
Test-Parameters: testgroup=review-dne-part-4 env=ENABLE_QUOTA=yes
Signed-off-by: Sergey Cheremencev <scherementsev@ddn.com>
Change-Id: Ia6b034739cfe800c6661f199420d0a4dbe7110fc
Reviewed-on: https://review.whamcloud.com/c/fs/lustre-release/+/49823
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Jian Yu <yujian@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>