BUG/MEDIUM: lua/htx: Handle EOM in receive/get_line calls in HTTP applets

BUG/MEDIUM: lua/htx: Handle EOM in receive/get_line calls in HTTP applets

In HTTP applets, the request's EOM was removed like other blocks when receive or
get_line was called from lua scripts. So it was impossible to stop receiving
data on successive calls when all the request body was already consumed,
blocking infinitly the applet.

Now, we never consume the EOM. So it is easy to interrupt receive/get_line
calls. In all cases, this block is consumed when the applet ends.