BUG/MEDIUM: h1-htx: Don't report EOM for H1 interim responses during parsing

BUG/MEDIUM: h1-htx: Don't report EOM for H1 interim responses during parsing

Commit b7467ca91 ("MAJOR: htx: Use htx_set_eom() instead of setting
HTX_FL_EOM by hand") introduced a regression. During H1 response parsing,
the end of the message was reported in 1XX interim responses, while it
should not. Because of this issue, a BUG_ON() was triggered on the final
response parsing.

The calls to htx_set_eom() function in h1_postparse_req_hdrs() and
h1_postparse_res_hdrs() was factorized to be always set when the parser
reached H1_MSG_DONE state. This was obviously wrong for 1XX interim
messages.

Thanks to Adam Crawford for reporting this issue.

It is a 3.5-specific issue. No backport needed.