BUG/MINOR: peers: don't count track-sc multiple times on errors

Ruoshan Huang found that the call to session_inc_http_err_ctr() in the
recent http-response patch was not a good idea because it also increments
counters that are already tracked (eg: http-request track-sc or previous
http-response track-sc). Better open-code the update, it's simple.
1 file changed