Revert "fix kvm issue, for windows sever 2008, it will crash without hyperv enlightment featre enabled"

This reverts commit c9dcae548056aa477e4156a1ec2efc9a83813aed.
Revert "There are few cases that mgt server won't reponse agent's pingcommand timely, or in KVM's case, libvirt won't repsonse in few mintues, which will cause agent reconnect to mgt server, then all the on going tasks on host will fail"

This reverts commit f3e91bf26acaeb1202e1fa84b70ad24db3a0eace.