EX-4098 lipe: lpcc uses class only in python3

EX-4098 lipe: lpcc uses class only in python3

FileNotFoundError is only available from python3.
Change it to matching class in python2.

Change-Id: I63676ef8ff6a5461a7af6e9177d6bc76e39c0bc5
Signed-off-by: Lei Feng <flei@whamcloud.com>
Test-Parameters: trivial testlist=sanity-pcc env=ONLY=200-202,ONLY_REPEAT=50 \
                 clientextra_install_params="--packages lipe-lpcc"
Reviewed-on: https://review.whamcloud.com/45304
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Minh Diep <mdiep@whamcloud.com>