Fix fulltext indexing when increasing a version on document modification

Steps to reproduce:

• Log in http://lts.nuxeo.com/
• Go to your personal workspace
• Create a Note document with these metadata:
  • title: note1
• Go to the advanced search screen and fill the Title field with "note1" => the Note document is in the results
• Go back to the Note document and edit it with :
  • title: note2
• Save with major version increment
• Go to the advanced search screen and fill the Title field with "note2" => no result
• Fill the Title field with "note1" => the Note document is in the results

The two last steps show the document is not indexed when the version is incremented.