Can't find files with special characters with BDE

build:nuxeo-server-9.10-I20171211_2311-tomcat
mongo and redis environment

Steps to reproduce:

• Create a folder and import files with special characters in their titles, like "Medium_Lanscape.jpg"
• Open the browser extension
• In the Search repository field type: "Medium_Landscape"
  => it doesn't find any file
• Type "medium"
  => the file appears.