OAIRepository: CFG_OAI_REPOSITORY_MARCXML_SIZE

* Increases CFG_OAI_REPOSITORY_MARCXML_SIZE from 100 to
  1000 in order to reduce the overhead due to bibupload
  creation.

Reviewed-by: Tibor Simko <tibor.simko@cern.ch>
Merge branch 'maint-1.1'

* maint-1.1:
  OAIRepository: CFG_OAI_REPOSITORY_MARCXML_SIZE