qa/suites/krbd: use a standard fixed-1 cluster in unmap subsuite

A custom "fixed-1, but with the client on a separate node" cluster was
needed only for pre-single-major.yaml kernel which is no longer around.
This can be a single-node job now -- see commits 311a450
("krbd/unmap: put client.0 on a separate remote") and 39a5791
("qa/suites/krbd: drop pre-single-major test").

Signed-off-by: Ilya Dryomov <[email protected]>

Author: idryomov

qa/suites/krbd/unmap/clusters/fixed-1.yaml

@@ -0,0 +1 @@
+.qa/clusters/fixed-1.yaml