Update dogpile-cache to 1.1.5
Update dogpile-cache to 1.1.5

To match u-c and fix known issues with pymemcache [1].

[1] https://bugzilla.redhat.com/show_bug.cgi?id=1977711

Change-Id: Ie01f99c4c34f29a6b3b1fa322fabb98b8ccaba80

redhat-openstack/rdoinfo