B #1484: Do not nul CPU usage if cloudwatch doesn't return value
B #1484: Do not nul CPU usage if cloudwatch doesn't return value

(cherry picked from commit 98f6fe58498ef64bbc761e67a6dc262975c88af3)

atodorov-storpool/one,baby-gnu/one,baby-gnu/one,baby-gnu/one,atodorov-storpool/one,OpenNebula/one,baby-gnu/one,OpenNebula/one,OpenNebula/one,baby-gnu/one,atodorov-storpool/one,OpenNebula/one,baby-gnu/one,baby-gnu/one,atodorov-storpool/one,OpenNebula/one,atodorov-storpool/one,OpenNebula/one,OpenNebula/one,baby-gnu/one,OpenNebula/one,atodorov-storpool/one,atodorov-storpool/one,atodorov-storpool/one,atodorov-storpool/one,OpenNebula/one