Fix runtime error in service group watch when service undefined

[spadgett]

@jwforres PTAL

[spadgett]

Fixes:

angular.js:11706 TypeError: Cannot read property 'metadata' of undefined
    at serviceGroup.js:68
    at watchGroupAction (angular.js:14105)
    at Scope.$eval (angular.js:14570)
    at Scope.$digest (angular.js:14386)
    at Scope.$apply (angular.js:14675)
    at done (angular.js:9725)
    at completeRequest (angular.js:9915)
    at XMLHttpRequest.requestLoaded (angular.js:9856)

[spadgett]

@jwforres hold, unserviced RCs are not showing up :(

[spadgett]

[merge]

[openshift-bot]

Origin Web Console Merge Results: SUCCESS (https://ci.openshift.redhat.com/jenkins/job/test_pull_requests_origin_web_console/46/)

[openshift-bot]

Evaluated for origin web console merge up to d904e41