json rpc: loop until ping2 is successful on the new connection
json rpc: loop until ping2 is successful on the new connection

Call __vdsm_json_rpc_check inside the while loop,
Raise the observation time from 15 to 20 seconds
to be sure that we wait enough time for vdsm
exiting the recovery status.

Change-Id: I2f2aee7d49b63413631016c8596b5a8e95bb704b
Bug-Url: https://bugzilla.redhat.com/1512534
Signed-off-by: Simone Tiraboschi <cb03129c66ba4da7ba7044049d0f43907bf857bb@redhat.com>

oVirt/ovirt-hosted-engine-ha,oVirt/ovirt-hosted-engine-ha,oVirt/ovirt-hosted-engine-ha,oVirt/ovirt-hosted-engine-ha