BUG/MEDIUM: httpclient: must manipulate head, not first

The httpclient mistakenly use the htx_get_first{_blk}() functions instead
of the htx_get_head{_blk}() functions. Which could stop the httpclient
because it will be without the start line, waiting for data that won't never
come.

Must be backported in 2.5.
1 file changed