When deleting a project, we should ignore missing Nuxeo project document

When deleting a project, if the Nuxeo document does not exist, we should only warn, but let the processus continue.

The raised exception makes Connect's cleaning task stops:

Name: mtdscan
Delete project: mtdscan
com.nuxeo.studio.client.model.NoSuchProjectException: No such project mtdscan
at com.nuxeo.studio.core.impl.NuxeoSession.getDocument(NuxeoSession.java:201)
at com.nuxeo.studio.core.impl.NuxeoSession.isBackupProjectRootNeeded(NuxeoSession.java:172)
at com.nuxeo.studio.core.impl.AbstractSession.deleteProject(AbstractSession.java:127)
at com.nuxeo.connect.service.NuxeoConnectComponent.deleteConnectClient(NuxeoConnectComponent.java:526)
at com.nuxeo.connect.cleaner.CleanerWork.work(CleanerWork.java:80)
at org.nuxeo.ecm.core.work.AbstractWork.runWorkWithTransaction(AbstractWork.java:342)
at org.nuxeo.ecm.core.work.AbstractWork.runWorkWithTransactionAndCheckExceptions(AbstractWork.java:303)
at org.nuxeo.ecm.core.work.AbstractWork.run(AbstractWork.java:272)
at org.nuxeo.ecm.core.work.WorkHolder.run(WorkHolder.java:52)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:745)
2016-01-15 13:00:02,632 ERROR [Nuxeo-Work-cleanerQueue-1] [com.nuxeo.connect.service.NuxeoConnectComponent] Client is Expired: /default-domain/connectRoot/clients/generali_dpierson
Name: generali_dpierson
Delete project: intranet-generali
com.nuxeo.studio.client.model.NoSuchProjectException: No such project intranet-generali
at com.nuxeo.studio.core.impl.NuxeoSession.getDocument(NuxeoSession.java:201)
at com.nuxeo.studio.core.impl.NuxeoSession.isBackupProjectRootNeeded(NuxeoSession.java:172)
at com.nuxeo.studio.core.impl.AbstractSession.deleteProject(AbstractSession.java:127)
at com.nuxeo.connect.service.NuxeoConnectComponent.deleteConnectClient(NuxeoConnectComponent.java:526)
at com.nuxeo.connect.cleaner.CleanerWork.work(CleanerWork.java:80)
at org.nuxeo.ecm.core.work.AbstractWork.runWorkWithTransaction(AbstractWork.java:342)
at org.nuxeo.ecm.core.work.AbstractWork.runWorkWithTransactionAndCheckExceptions(AbstractWork.java:303)
at org.nuxeo.ecm.core.work.AbstractWork.run(AbstractWork.java:272)
at org.nuxeo.ecm.core.work.WorkHolder.run(WorkHolder.java:52)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
at java.lang.Thread.run(Thread.java:745)
2016-01-15 13:00:02,716 ERROR [Nuxeo-Work-cleanerQueue-1] [com.nuxeo.connect.service.NuxeoConnectComponent] Client is Expired: /default-domain/connectRoot/clients/acg
Name: acg
Delete project: 1-acg
com.nuxeo.studio.client.model.NoSuchProjectException: No such project 1-acg
at com.nuxeo.studio.core.impl.NuxeoSession.getDocument(NuxeoSession.java:201)
at com.nuxeo.studio.core.impl.NuxeoSession.isBackupProjectRootNeeded(NuxeoSession.java:172)
at com.nuxeo.studio.core.impl.AbstractSession.deleteProject(AbstractSession.java:127)
at com.nuxeo.connect.service.NuxeoConnectComponent.deleteConnectClient(NuxeoConnectComponent.java:526)
at com.nuxeo.connect.clea