[TECHNICAL-SUPPORT | August 19] LPS-49094 Upgrade pdfbox from 1.8.2 to 1.8.6

https://issues.liferay.com/browse/LPS-49094

Hey Roberto,

I'm sending this pull to you since Sergio is on Holiday (based on his Google Calendar at least :-)) and Máté informed me that you can replace him for DM related pulls.

Regards,
Tibor