The parse-ppa-apache-access-logs.py script should report an error parsing a log line just once

[Guruprasad]

When the parser encounters an invalid line, it throws an error at that point and does not proceed to parse the remaining lines in the log file. On subsequent invocation of the script via a cron job, it resumes parsing at the same line and fails again and again till the log file containing the bad log line is rotated out and is no longer on disk.

Fix this to parse all the log lines in a file even when there are a few invalid lines in it, and report the error just once.