Fix CSV import with document properties

Steps to reproduce:

• Navigate to a Folder.
• Click on the Add Content button.
• Click on the CSV tab.
• Click on Click to select a csv file or drag it to upload. and upload the attached CSV file.
• Click on Create
  => The files were not imported.
  => The following errors appear:

  Line 2 ERROR Unable to create document
  Line 3 ERROR Unable to create document

  => The cursor changes to a pointer when hovering over the error messages, as if they were clickable, but clicking on them does nothing.
  => The following errors appear in the server.log:

  2018-11-19T14:50:38,409 ERROR [Nuxeo-Work-csvImporter-1:default:/domain-1/workspaces/workspace-1/csv-folder-1:csvImport:1ba58510940a3f767bdbc49bbbc03771] [org.nuxeo.ecm.csv.core.CSVImporterWork] Line 2: Unable to create document: For input string: "01/0"
  2018-11-19T14:50:38,409 ERROR [Nuxeo-Work-csvImporter-1:default:/domain-1/workspaces/workspace-1/csv-folder-1:csvImport:1ba58510940a3f767bdbc49bbbc03771] [org.nuxeo.ecm.csv.core.CSVImporterWork] Line 3: Unable to create document: For input string: "01/0"