Description of problem:
The OFV parser tries to read the VM ID attribute from the first <Section>
tag in the file. If the VM is part of an affinity group, the <Section>
containing affinity information is before the <Section> with VM ID.
This causes the parsing to fail and the agent crashes.

The error is:
MainThread::ERROR::2018-02-14 11:23:05,214::hosted_engine::434::ovirt_hosted_engine_ha.agent.hosted_engine.HostedEngine::(start_monitoring) Unhandled monitoring loop exception
Traceback (most recent call last):
  File "/usr/lib/python2.7/site-packages/ovirt_hosted_engine_ha/agent/hosted_engine.py", line 431, in start_monitoring
    self._monitoring_loop()
  File "/usr/lib/python2.7/site-packages/ovirt_hosted_engine_ha/agent/hosted_engine.py", line 450, in _monitoring_loop
    for old_state, state, delay in self.fsm:
  File "/usr/lib/python2.7/site-packages/ovirt_hosted_engine_ha/lib/fsm/machine.py", line 127, in next
    new_data = self.refresh(self._state.data)
  File "/usr/lib/python2.7/site-packages/ovirt_hosted_engine_ha/agent/state_machine.py", line 123, in refresh
    ] = self.hosted_engine.min_memory_threshold
  File "/usr/lib/python2.7/site-packages/ovirt_hosted_engine_ha/agent/hosted_engine.py", line 184, in min_memory_threshold
    return int(self._config.get(config.VM, config.MEM_SIZE))
  File "/usr/lib/python2.7/site-packages/ovirt_hosted_engine_ha/env/config.py", line 213, in get
    self._load_config_files(dict([(type, self._dynamic_files[type])]))
  File "/usr/lib/python2.7/site-packages/ovirt_hosted_engine_ha/env/config.py", line 201, in _load_config_files
    self.refresh_local_conf_file(config_type)
  File "/usr/lib/python2.7/site-packages/ovirt_hosted_engine_ha/env/config.py", line 385, in refresh_local_conf_file
    result = refresh_method()
  File "/usr/lib/python2.7/site-packages/ovirt_hosted_engine_ha/env/config.py", line 515, in refresh_vm_conf
    content_from_ovf = self._get_vm_conf_content_from_ovf_store()
  File "/usr/lib/python2.7/site-packages/ovirt_hosted_engine_ha/env/config.py", line 443, in _get_vm_conf_content_from_ovf_store
    conf = ovf2VmParams.confFromOvf(heovf)
  File "/usr/lib/python2.7/site-packages/ovirt_hosted_engine_ha/lib/ovf/ovf2VmParams.py", line 298, in confFromOvf
    vmConf = toDict(ovf)
  File "/usr/lib/python2.7/site-packages/ovirt_hosted_engine_ha/lib/ovf/ovf2VmParams.py", line 222, in toDict
    vmParams['vmId'] = tree.find('Content/Section').attrib[OVF_NS + 'id']
  File "lxml.etree.pyx", line 2272, in lxml.etree._Attrib.__getitem__ (src/lxml/lxml.etree.c:55336)
KeyError: '{http://schemas.dmtf.org/ovf/envelope/1}id'


Version-Release number of selected component (if applicable):
ovirt-hosted-engine-ha   2.2.2-1.el7.centos

How reproducible:
100%

Steps to Reproduce:
1. Create an affinity group containing the HE VM.
2. Edit the HE VM, so the new OVF is saved to the storage domain. (For example, change maximum memory)
3. Wait a while and look to the HA agent logs

Actual results:
The agent keeps crashing with the above error.

Expected results:
The agent starts normally.