short messages truncated to 64 chars

Hello there!

I am using nxlog for tailing specific files (im_file) and output them via GELF_TCP to Graylog which goes good except 1 thing > short_messages get truncated to 64 chars which, if I understand right, is related to this directive (or I might be wrong):

AskedAugust 24, 2015 - 7:02pm