fix 'Error reading resource from path "/"' when deployed without Offline project

[StephanSchrader]

When OpenCms instance is deployed without the 'Offline' project, an error message is logged once after restart.

05 Nov 2015 19:00:33,862 ERROR [guration.CmsConfigurationCache: 436] [ - ] Error reading resource from path "/".
org.opencms.file.CmsVfsResourceNotFoundException: Error reading resource from path "/".
        at org.opencms.file.CmsVfsResourceNotFoundException.createException(CmsVfsResourceNotFoundException.java:71)
        at org.opencms.db.CmsDbContext.throwException(CmsDbContext.java:334)
        at org.opencms.db.CmsDbContext.report(CmsDbContext.java:286)
        at org.opencms.db.CmsSecurityManager.readResource(CmsSecurityManager.java:4938)
        at org.opencms.file.CmsObject.readResource(CmsObject.java:3078)
        at org.opencms.file.CmsObject.readResources(CmsObject.java:3115)
        at org.opencms.file.CmsObject.readResources(CmsObject.java:3096)
        at org.opencms.ade.configuration.CmsConfigurationCache.loadElementViews(CmsConfigurationCache.java:427)
        at org.opencms.ade.configuration.CmsConfigurationCache.readCompleteConfiguration(CmsConfigurationCache.java:316)
        at org.opencms.ade.configuration.CmsConfigurationCache.initialize(CmsConfigurationCache.java:244)
        at org.opencms.ade.configuration.CmsADEManager.initialize(CmsADEManager.java:825)
        at org.opencms.main.OpenCmsCore.getADEManager(OpenCmsCore.java:404)
        at org.opencms.main.OpenCms.getADEManager(OpenCms.java:179)
        at org.opencms.xml.containerpage.CmsXmlContainerPageFactory.getCache(CmsXmlContainerPageFactory.java:417)
        at org.opencms.xml.containerpage.CmsXmlContainerPageFactory.getCache(CmsXmlContainerPageFactory.java:434)
        at org.opencms.xml.containerpage.CmsXmlContainerPageFactory.unmarshal(CmsXmlContainerPageFactory.java:222)
        at org.opencms.xml.containerpage.CmsXmlContainerPageFactory.unmarshal(CmsXmlContainerPageFactory.java:190)
        at org.opencms.xml.containerpage.CmsXmlContainerPageFactory.unmarshal(CmsXmlContainerPageFactory.java:162)
        at org.opencms.search.solr.CmsSolrDocumentContainerPage.extractContent(CmsSolrDocumentContainerPage.java:172)
        at org.opencms.search.solr.CmsSolrDocumentContainerPage.createDocument(CmsSolrDocumentContainerPage.java:148)
        at org.opencms.search.CmsIndexingThread.createIndexDocument(CmsIndexingThread.java:227)
        at org.opencms.search.CmsIndexingThread.run(CmsIndexingThread.java:117)
Caused by: org.opencms.file.CmsVfsResourceNotFoundException: Unable to read resource "/".
        at org.opencms.db.generic.CmsVfsDriver.readResource(CmsVfsDriver.java:2331)
        at org.opencms.ocee.cache.CmsVfsCache.readResource(CmsVfsCache.java:860)
        at org.opencms.db.CmsDriverManager.readResource(CmsDriverManager.java:7490)
        at org.opencms.db.CmsSecurityManager.readResource(CmsSecurityManager.java:7278)
        at org.opencms.db.CmsSecurityManager.readResource(CmsSecurityManager.java:4936)
        ... 20 more

[tHerrmann]

Hi Stephan,
thanks for your effort. this will be included in the comming releases of OpenCms.

Regards, Tobias