CLOUDSTACK-8011: Fix httpcore/client and commons-httpclient version usage

- httpcore and httpclient are sharing same version variable
- commons-httpclient is different that httpclient, the fix gives it a separate var

Signed-off-by: Rohit Yadav <rohit.yadav@shapeblue.com>
pom: downgrade reflections to 0.9.8

Apidocs fail to generate and get stuck with new reflections version, the fix
downgrades reflections pkg dependency version to 0.9.8

Signed-off-by: Rohit Yadav <rohit.yadav@shapeblue.com>