Fix handling empty url string for Health Check
Fix handling empty url string for Health Check

Issue:
------
when url string is empty http parser does not seems to
return error and urldata being uninitialised cause
invalid length access in string.

Fix:
----
skip url parsing if url path is empty, this will allow
health check to fallback default to
"http:://<vmi-instance-ip>"

Change-Id: Iba608d01fa89656a7b902ca4781331ca60ac9789
Closes-Bug:1548702

rombie/contrail-controller,rombie/contrail-controller,nischalsheth/contrail-controller,nischalsheth/contrail-controller,tcpcloud/contrail-controller,codilime/contrail-controller,tcpcloud/contrail-controller,codilime/contrail-controller,rombie/contrail-controller,eonpatapon/contrail-controller,nischalsheth/contrail-controller,rombie/contrail-controller,nischalsheth/contrail-controller,eonpatapon/contrail-controller,codilime/contrail-controller,nischalsheth/contrail-controller,codilime/contrail-controller,rombie/contrail-controller,tcpcloud/contrail-controller,rombie/contrail-controller,tcpcloud/contrail-controller,eonpatapon/contrail-controller,codilime/contrail-controller,tcpcloud/contrail-controller,rombie/contrail-controller,tcpcloud/contrail-controller,eonpatapon/contrail-controller,codilime/contrail-controller,nischalsheth/contrail-controller,nischalsheth/contrail-controller,eonpatapon/contrail-controller,nischalsheth/contrail-controller,eonpatapon/contrail-controller,eonpatapon/contrail-controller