Fix use of wrong label static test fixture

The unresolvable host needs to have the same label as the resolvable
host. Otherwise the test is not checking if only the resolvable host was
registered.

Change-Id: Ie7330361e8afce33303517f8e31a0f3483d903ea

nodepool/tests/fixtures/static-unresolvable.yaml

@@ -5,7 +5,6 @@ zookeeper-servers:
 
 labels:
   - name: fake-label
-  - name: fake-label-unresolvable
 
 providers:
   - name: static-provider
@@ -14,7 +13,8 @@ providers:
       - name: main
         nodes:
           - name: unresolvable.unresolvable.unresolvable
-            labels: fake-label-unresolvable
+            labels: fake-label
+            host-key: ssh-rsa FAKEKEY
             timeout: 13
             connection-port: 22022
             username: zuul