Correct request logging query parameters separator
Correct request logging query parameters separator

The trailing ? was always in the URL even when there were no
parameters. Now when there's no parameters there will be no ?.

Change-Id: Idb001e78b72adb1b88da20a8652bf152746bf32b

takeshineshiro/keystone,dstanek/keystone,idjaw/keystone,himanshu-setia/keystone,dims/keystone,rajalokan/keystone,jamielennox/keystone,vivekdhayaal/keystone,dims/keystone,mahak/keystone,vivekdhayaal/keystone,mahak/keystone,takeshineshiro/keystone,ilay09/keystone,cernops/keystone,maestro-hybrid-cloud/keystone,mahak/keystone,openstack/keystone,rajalokan/keystone,maestro-hybrid-cloud/keystone,jamielennox/keystone,vivekdhayaal/keystone,jonnary/keystone,dstanek/keystone,roopali8/keystone,himanshu-setia/keystone,klmitch/keystone,ajayaa/keystone,idjaw/keystone,jonnary/keystone,ilay09/keystone,rajalokan/keystone,dstanek/keystone,openstack/keystone,openstack/keystone,roopali8/keystone,ajayaa/keystone,cernops/keystone,klmitch/keystone,ilay09/keystone