Add voting to OpenSuse jobs

Voting was previously turned off due to instability with OpenSUSE
mirrors.  This appears to have been resolved over the last week so
this patch re-adds voting.

Change-Id: I293d298996468fee43db410ea54911aef7852a9a

.zuul.yaml

@@ -70,7 +70,6 @@
 - job:
     name: spyglass-docker-build-gate-opensuse
     timeout: 1800
-    voting: false
     run: tools/gate/playbooks/docker-image-build.yaml
     nodeset: spyglass-single-node
     vars:
@@ -117,7 +116,6 @@
 - job:
     name: spyglass-docker-publish-opensuse
     timeout: 1800
-    voting: false
     run: tools/gate/playbooks/docker-image-build.yaml
     nodeset: spyglass-single-node
     secrets: