shadowsocks-libev: validate bool with default value 0

The change is mainly for keeping compatibility with old validate_data
before ubox commit ac481cdd999ee84d3f115c33a56397237e95ec64 in Sat Jul
16 14:52:36 2016 +0200.  The behaviour change comes with that commit can
be seen with the following command line session

    root@LEDE:/usr/bin# validate_data network interface wan 'disabled:bool:false'
    network.wan.disabled is unset and defaults to bool false
    disabled=0; root@LEDE:/usr/bin#

    root@OpenWrt:/# validate_data network interface lan 'disabled:bool:false'
    disabled='false'; root@OpenWrt:/#

This will cause shadowsocks-libev in current master branch fail on OpenWrt
15.01 though they actually should only use packages from the 15.01 branch...

Fixes openwrt/packages#4614

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

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

@@ -241,7 +241,7 @@ validate_common_server_options_() {
 	local aead_methods='"aes-128-gcm", "aes-192-gcm", "aes-256-gcm"'
 
 	"${func:-ss_validate}" "$cfgtype" "$cfg" "$@" \
-		'disabled:bool:false' \
+		'disabled:bool:0' \
 		'server:host' \
 		'server_port:port' \
 		'password:string' \
@@ -262,10 +262,10 @@ validate_common_options_() {
 	local func="$1"; shift
 
 	"${func:-ss_validate}" "$cfgtype" "$cfg" "$@" \
-		'disabled:bool:false' \
-		'verbose:bool:false' \
-		'fast_open:bool:false' \
-		'reuse_port:bool:false' \
+		'disabled:bool:0' \
+		'verbose:bool:0' \
+		'fast_open:bool:0' \
+		'reuse_port:bool:0' \
 		'mode:or("tcp_only", "udp_only", "tcp_and_udp")' \
 		'mtu:uinteger' \
 		'timeout:uinteger' \
@@ -286,7 +286,7 @@ validate_ss_redir_section() {
 
 validate_ss_rules_section() {
 	"${2:-ss_validate}" ss_rules "$1" \
-		'disabled:bool:false' \
+		'disabled:bool:0' \
 		'redir_tcp:uci("shadowsocks-libev", "@ss_redir")' \
 		'redir_udp:uci("shadowsocks-libev", "@ss_redir")' \
 		'src_ips_bypass:list(ipaddr)' \