shadowsocks-libev: bump to version 3.1.3

Notable changes since 3.1.2

    afce1b3 eliminate timered delay between handshake and data stream #1572
    539bf6e sni in redir removed and no disable_sni option #1876
    1d94442..29ff5d3 udprelay fix (no idea what's the problem...) #1883

Now disable_sni=true is the default.  Existing uci configs setting it
will be a nop

Signed-off-by: Yousong Zhou <yszhou4tech@gmail.com>

net/shadowsocks-libev/files/shadowsocks-libev.init

@@ -78,11 +78,7 @@ ss_mkjson_ss_local_conf() {
 }
 
 ss_mkjson_ss_redir_conf() {
-	ss_mkjson_server_conf || return 1
-	[ "$disable_sni" = 0 ] && disable_sni=false || disable_sni=true
-	cat <<-EOF
-		"disable_sni": $disable_sni,
-	EOF
+	ss_mkjson_server_conf
 }
 
 ss_mkjson_ss_server_conf() {
@@ -276,9 +272,7 @@ validate_ss_local_section() {
 }
 
 validate_ss_redir_section() {
-	validate_common_client_options_ ss_redir "$1" \
-		"${2}" \
-		'disable_sni:bool:0'
+	validate_common_client_options_ ss_redir "$1" "${2}"
 }
 
 validate_ss_rules_section() {