Keystone EC2 access keys may contain URL reserved/unsafe chars,
then the access key in PATH_INFO can't be replace by account name.
ie.
/v1/abc%3D/c/o --> /v1/AUTH_PROJECT_ID/c/o
Change-Id: I034b0902f620cbb274647e24566dff2031beeae5
Closes-Bug: 1776476