BUG/MINOR: http-fetch: Update method after a prefetch in smp_fetch_meth()

In smp_fetch_meth(), smp_prefetch_htx() function may be called to parse the
HTX message and update the HTTP transaction accordingly. In this case, in
smp_fetch_metch() and on success, we must update "meth" variable. Otherwise,
the variable is still equal to HTTP_METH_OTHER and the string version is
always used instead of the enum for known methods.

This patch must be backported as far as 2.0.

(cherry picked from commit eefcd8a97de7d1b05b38d240b1061e2f2112f2f8)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>
(cherry picked from commit 7e22d25354b7c768c720ab1301aaae8c8573e9dd)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>
(cherry picked from commit e72c990339befdf0debf71a35b010512380d2b05)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>
diff --git a/src/http_fetch.c b/src/http_fetch.c
index a66be20..7819df6 100644
--- a/src/http_fetch.c
+++ b/src/http_fetch.c
@@ -342,6 +342,7 @@
 		htx = smp_prefetch_htx(smp, chn, NULL, 1);
 		if (!htx)
 			return 0;
+		meth = txn->meth;
 	}
 
 	smp->data.type = SMP_T_METH;