BUG/MINOR: hlua: Properly enable/disable receives for TCP applets
From a lua TCP applet, in functions used to retrieve data (receive,
try_receive and getline), we must take care to disable receives when data
are returned (or on failure) and to restart receives when these functions
are called again. In addition, when an applet execution is finished, we must
restart receives to properly drain the request.
This patch should be backported to 3.3. On older version, no bug was
reported so we can wait a report first.