sometimes cluster recovery didn't work
because we only look for the sequence number in the last 200 lines
of the log file.

fix this by ingesting the complete file and only register the last
sequence number we find.

Closes-Bug: 1821173

Change-Id: Iea2661c9d5d262cf99edd5f5b567f252607a0003
Signed-off-by: Sven Kieske <kieske@osism.tech>