Old code used to reduce packet size by one byte to remove space in
HTTP Host header. This introduces one unACKed byte which OS later
tried to send to the host. This byte was \n (the last byte in original
packet) which broke POST requests.
New code in this commit moves "stolen" space in the end of User-Agent
header value and do not reduce packet size anymore.
User-Agent value is used because not all web servers are compatible
with additional space in the end of Host value.
Fix#3
