Issues with integrity check

Hi all,
I have some trouble trying to install/set up PIWIK. The system check notifies an issue on integrity check. It says that has not the expected size of 117 but 115. As a hint to solve this it says to upload the PIWIK directory again using BINARY-mode.
My question: How can I do that? (or can I even ignore that message?) I use the latest version of FileZilla, which worked correctly for all other uploads, I did not find any setting or option for a BINARY mode.
Any idea?
Many thanks in advance
Best regards

Ignore the warning and click next?