This is a preparatory patch that renames the 'local' and 'local_length'
members of the nxt_unit_request_t structure to 'local_addr' and
'local_addr_length' in preparation for the adding of 'local_port' and
'local_port_length' members.
Suggested-by: Zhidao HONG <z.hong@f5.com>
Signed-off-by: Andrew Clayton <a.clayton@nginx.com>