Overlapping protocol packet causing a block

[Diastro]

Socket communication wasn't using delimiters which cause (in rare cases since I test Zeek running multiple python process on the same server) the ServerSideClient to block on a read eventhough it had received more then a full packet.

Fix:
Added a delimiter and after receiving data we check to see if there's a delimiter in the buffer. If so, we take the complete packet that's in there.