luci-app-ssr-plus: disable IPv6 in MOSDNS query mode by default

luci-app-ssr-plus/luasrc/model/cbi/shadowsocksr/client.lua

@@ -134,7 +134,7 @@ o.description = translate("Custom DNS Server for mosdns")
 o = s:option(Flag, "mosdns_ipv6", translate("Disable IPv6 in MOSDNS query mode"))
 o:depends("pdnsd_enable", "3")
 o.rmempty = false
-o.default = "0"
+o.default = "1"
 
 if is_finded("chinadns-ng") then
 	o = s:option(Value, "chinadns_forward", translate("Domestic DNS Server"))