add ensure_vr_is_running function
add ensure_vr_is_running function

This patch can work around http://dev.zstack.io/browse/ZSTAC-5595

zstackio/zstack-woodpecker,zstackorg/zstack-woodpecker,zstackorg/zstack-woodpecker,zstackio/zstack-woodpecker,zstackorg/zstack-woodpecker,zstackio/zstack-woodpecker