cubicweb #2131435 BFSS might fail on Windows if files are stored on a samba share [validation pending]

The reading / writing for BFSS are not performed using chunking which is known to fail on Windows SMB shares.

prioritynormal
typebug
done in3.14.2
load left0.000
closed by#a6654712ad50 fix potential problems when BFSS uses a Windows SMB share (closes #2131435)