BUG/BUILD: h3: fix wrong label name

A pretty ugly mistake introduced recently with an invalid goto statement
which prevents QUIC compilation on haproxy.

This must be backported on 2.6 as a complement to
  60ef19f137bad8cd97598970c708dd0bf4a89a70
  BUG/MINOR: h3/qpack: deal with too many headers
1 file changed