Fixing bug in path validation in system settings. Now empty strings are allowed (that means nothing is configured).
Fixing bug in path validation in system settings. Now empty strings are allowed (that means nothing is configured).

NicolasSchnitzler/medInria-public,aabadie/medInria-public,rdebroiz/medInria-public,aabadie/medInria-public,NicolasSchnitzler/medInria-public,rdebroiz/medInria-public,aabadie/medInria-public,NicolasSchnitzler/medInria-public,rdebroiz/medInria-public