Fix bug when reading last block during comment

Hi Dmitry,

I am using your library for a project at PayPal.  I recently uncovered a bug in `lineReader`.  I just happened to have a properties file with a comment line spanning the 1K boundary.  I dug into the code and found the problem.  The test case I created demonstrates the problem and will fail without the fix.

Please accept this patch.  I'd really like to continue using your repo!

thanks,
mike