Partially fix a bug when receiving empty messages.
Partially fix a bug when receiving empty messages.

The split method on an empty message block returns an array of length 1,
but the code was accessing at offset 1 (length >= 2).  The query test
tool was not putting a newline in the block.  More investigation is
likely needed.

Automated testing would help.

nitrogenlogic/xap_ruby,nitrogenlogic/xap_ruby