EX-6298 lipe: Decrease wait time to reconnect to ALR

EX-6298 lipe: Decrease wait time to reconnect to ALR

1) Made delay between reconnections to ALR gradually increasing
starting from as little as 5 seconds when ssh session
to ALR fails. It makes attempt to reconnect more often
initially.
2) Enable hot-pools test 72 previously excepted

Signed-off-by: Alexandre Ioffe <aioffe@ddn.com>
Test-Parameters: trivial testlist=hot-pools mdtcount=6 env=ONLY=72,ONLY_REPEAT=40
Change-Id: Iafae62d733390f92370f5d224830944f285da934
Reviewed-on: https://review.whamcloud.com/c/ex/lustre-release/+/49106
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>