BUG/MINOR: mux-h1: Check h1m flags to set the server conn_mode on request path

On the server side, we must test the request headers to deduce if we able to do
keepalive or not. Otherwise, by default, the keepalive will be enabled on the
server's connection, whatever the client said.
diff --git a/src/mux_h1.c b/src/mux_h1.c
index db63890..4646812 100644
--- a/src/mux_h1.c
+++ b/src/mux_h1.c
@@ -653,6 +653,12 @@
 			  h1m->flags & H1_MF_CONN_CLO))                    /* explicit close */
 			h1s->flags = (h1s->flags & ~H1S_F_WANT_MSK) | H1S_F_WANT_CLO;
 	}
+	else {
+		if (h1s->flags & H1S_F_WANT_KAL &&
+		    (!(h1m->flags & (H1_MF_VER_11|H1_MF_CONN_KAL)) || /* no KA in HTTP/1.0 */
+		     h1m->flags & H1_MF_CONN_CLO))                    /* explicit close */
+			h1s->flags = (h1s->flags & ~H1S_F_WANT_MSK) | H1S_F_WANT_CLO;
+	}
 
 	/* If KAL, check if the backend is stopping. If yes, switch in CLO mode */
 	if (h1s->flags & H1S_F_WANT_KAL && be->state == PR_STSTOPPED)