session_driver: Quickfix to prevent looped analog data reads.
A local buffer was too small, snprintf() was used to write the
name of the analog-1-1-xxx ZIP archive names in that buffer.
Due to the limited size, only 3 characters were usable for the last
number component, i.e. the code would loop around from analog-1-1-999
to analog-1-1-100 (instead of analog-1-1-1000).
As a quickfix, increase the buffer size by a large margin, a nicer
fix should be used later on.