Bugfix: heat conext of test case yamls jinja2 bypass sriov type

Bugfix: heat conext of test case yamls jinja2 bypass sriov type

the "if provider" condition bypass when provider = "sriov",
related to https://gerrit.opnfv.org/gerrit/#/c/32789/

  networks:
    test:
      cidr: '10.0.1.0/24'
      {% if provider == "vlan" %}
      provider: {{provider}}
      physical_network: {{physical_network}}
        {% if segmentation_id %}
      segmentation_id: {{segmentation_id}}
        {% endif %}
      {% endif %}

JIRA: YARDSTICK-1242

Change-Id: I6a611e839654f401648d9bd6188589816f7b4946
Signed-off-by: rexlee8776 <limingjiang@huawei.com>