Keep py3.X compatibility for urllib.urlencode
Keep py3.X compatibility for urllib.urlencode

For py3.X, urllib has no attr urlencode while python 2 has.
Change urlencode to keep compatibility.

Partial-Bug: #1280105

Change-Id: I2c0447af3206cdfc55ba22748b2793de8eb94cfb

isyippee/ceilometer,chungg/aodh,idegtiarov/ceilometer,NeCTAR-RC/ceilometer,Juniper/ceilometer,idegtiarov/ceilometer,redhat-openstack/ceilometer,pkilambi/ceilometer,m1093782566/openstack_org_ceilometer,ityaptin/ceilometer,sileht/aodh,luogangyi/Ceilometer-oVirt,openstack/ceilometer,m1093782566/openstack_org_ceilometer,isyippee/ceilometer,luogangyi/Ceilometer-oVirt,ityaptin/ceilometer,NeCTAR-RC/ceilometer,maestro-hybrid-cloud/ceilometer,mathslinux/ceilometer,maestro-hybrid-cloud/ceilometer,fabian4/ceilometer,cernops/ceilometer,MisterPup/Ceilometer-Juno-Extension,pczerkas/aodh,pkilambi/ceilometer,froyobin/ceilometer,tanglei528/ceilometer,Juniper/ceilometer,openstack/ceilometer,fabian4/ceilometer,eayunstack/ceilometer,cernops/ceilometer,openstack/aodh,MisterPup/Ceilometer-Juno-Extension,NeCTAR-RC/ceilometer,redhat-openstack/ceilometer,eayunstack/ceilometer,r-mibu/ceilometer,pczerkas/aodh,chungg/aodh,froyobin/ceilometer,tanglei528/ceilometer,openstack/aodh,tanglei528/ceilometer,r-mibu/ceilometer,sileht/aodh,mathslinux/ceilometer