BUG/MINOR: dns: allow srv record weight set to 0

Processing of SRV record weight was inaccurate and when a SRV record's
weight was set to 0, HAProxy enforced it to '1'.
This patch aims at fixing this without breaking compability with
previous behavior.

Backport status: 1.8 to 2.0

(cherry picked from commit 25e6fc2030552499e42f202a2496e7f9bc634005)
Signed-off-by: Willy Tarreau <w@1wt.eu>
1 file changed