pre-upload: add missing space in the message

BUG=None
TEST=`./pre-upload_unittest.py` passes

Change-Id: I4153278dbd4372794c96ec8e800f453057d5c4ca
Reviewed-on: https://chromium-review.googlesource.com/271643
Reviewed-by: Dan Erat <derat@chromium.org>
Tested-by: Mike Frysinger <vapier@chromium.org>
1 file changed