Fix spurious logging for FileDiff insert/delete counts.
Review Request #6032 — Created June 26, 2014 and submitted
The logging statements for "overriding" insert and delete counts were
surrounded by conditionals that didn't quite reflect the reality of when things
get overridden. This fixes it so that we don't spam the log files.
Ran unit tests.
Tool: PEP8 Style Checker Processed Files: reviewboard/diffviewer/models.py Tool: Pyflakes Processed Files: reviewboard/diffviewer/models.py