Fix authentication of transientStoreGCStart scheduled event

2015-08-20 21:00:00,174 ERROR [Quartz_Worker-1] [org.nuxeo.ecm.core.scheduler.EventJob] Error while processing scheduled event id: transientStoreGCStart
javax.security.auth.login.LoginException: createIdentity failed for user Administrator
        at org.nuxeo.ecm.platform.login.NuxeoLoginModule.createIdentity(NuxeoLoginModule.java:279)
        at org.nuxeo.ecm.platform.login.NuxeoLoginModule.validateUserIdentity(NuxeoLoginModule.java:324)
        at org.nuxeo.ecm.platform.login.NuxeoLoginModule.getPrincipal(NuxeoLoginModule.java:191)
        at org.nuxeo.ecm.platform.login.NuxeoLoginModule.login(NuxeoLoginModule.java:232)
        at org.nuxeo.runtime.api.LoginModuleWrapper.login(LoginModuleWrapper.java:73)
        at sun.reflect.GeneratedMethodAccessor52.invoke(Unknown Source)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:497)
        at javax.security.auth.login.LoginContext.invoke(LoginContext.java:755)
        at javax.security.auth.login.LoginContext.access$000(LoginContext.java:195)
        at javax.security.auth.login.LoginContext$4.run(LoginContext.java:682)
        at javax.security.auth.login.LoginContext$4.run(LoginContext.java:680)
        at java.security.AccessController.doPrivileged(Native Method)
        at javax.security.auth.login.LoginContext.invokePriv(LoginContext.java:680)
        at javax.security.auth.login.LoginContext.login(LoginContext.java:587)
        at org.nuxeo.ecm.platform.ui.web.auth.NuxeoAuthenticationFilter.loginAs(NuxeoAuthenticationFilter.java:1060)
        at org.nuxeo.ecm.platform.ui.web.auth.service.LoginAsImpl.loginAs(LoginAsImpl.java:32)
        at org.nuxeo.runtime.api.Framework.loginAsUser(Framework.java:272)
        at org.nuxeo.ecm.core.scheduler.EventJob.execute(EventJob.java:94)
        at org.nuxeo.ecm.core.scheduler.EventJob.execute(EventJob.java:60)
        at org.quartz.core.JobRunShell.run(JobRunShell.java:223)
        at org.quartz.simpl.SimpleThreadPool$WorkerThread.run(SimpleThreadPool.java:549)
Caused by: javax.security.auth.login.LoginException: principal Administrator does not exist
        at org.nuxeo.ecm.platform.login.NuxeoLoginModule.createIdentity(NuxeoLoginModule.java:270)
        ... 21 more