MINOR : Switch to using a v2 object as required by the new interface

SVN: 28515

openbis-ipad/ipad-example-data/ipad-ui/1/dss/reporting-plugins/ipad-read-service-v1/ipad_read.py

-from ch.systemsx.cisd.openbis.dss.generic.shared.api.internal.v1 import MaterialIdentifierCollection
+from ch.systemsx.cisd.openbis.dss.generic.shared.api.internal.v2 import MaterialIdentifierCollection
 from ch.systemsx.cisd.openbis.generic.shared.basic.dto import MaterialIdentifier
 from com.fasterxml.jackson.databind import ObjectMapper 
 from ch.systemsx.cisd.openbis.generic.shared.api.v1.dto import SearchCriteria, SearchSubCriteria