[ethereum/go-ethereum] Light: admin.nodeInfo is showing wrong CHTRoot (#17458)

On custom network

«`
> admin.nodeInfo
{
enode: «enode://2b45d72abcda6472cf3ea8a232a9dfbc9eceb731302a0486a3fffb017dd55e9cb75cc68dab192ead284df3ab0aa238ecf79f64fae789c12af859b1a08265a9e4@[::]:25252»,
id: «2b45d72abcda6472cf3ea8a232a9dfbc9eceb731302a0486a3fffb017dd55e9cb75cc68dab192ead284df3ab0aa238ecf79f64fae789c12af859b1a08265a9e4»,
ip: «::»,
listenAddr: «[::]:25252»,
name: «EOSC/v2.1.1-unstable-6f029dcd/linux-amd64/go1.10»,
ports: {
discovery: 25252,
listener: 25252
},
protocols: {
eth: {
config: {
byzantiumBlock: 500000,
chainId: 20,
daoForkSupport: true,
disposalBlock: 100,
ecip1017EraRounds: 2500000,
eip100Block: 500000,
eip150Block: 0,
eip150Hash: «0xee8d34684cb1b1047a4bd326c43db0c85af8ffa82e9f54b6d557b4ad4eeb9135»,
eip155Block: 0,
eip158Block: 0,
ethash: {},
homesteadBlock: 0,
neweoscBlock: 150000
},
difficulty: 524598190527327300,
genesis: «0xee8d34684cb1b1047a4bd326c43db0c85af8ffa82e9f54b6d557b4ad4eeb9135»,
head: «0xc4fa3549432703b807a826683a849fde5f79b9d1b21111992a8913ba9497a067»,
network: 20
},
les: {
cht: {
BloomRoot: «0x184633e6b859e229c1b07c44d225ddfb62f31cf464243e810338b154c0b53c18»,
CHTRoot: «0x0000000000000000000000000000000000000000000000000000000000000000»,
SectionHead: «0x23c0c4a886b4b30faf01ee08db02fdef793e0a76bdf22bc809413f48e2fa0d80»,
SectionIdx: 12
},
config: {
byzantiumBlock: 500000,
chainId: 20,
daoForkSupport: true,
disposalBlock: 100,
ecip1017EraRounds: 2500000,
eip100Block: 500000,
eip150Block: 0,
eip150Hash: «0xee8d34684cb1b1047a4bd326c43db0c85af8ffa82e9f54b6d557b4ad4eeb9135»,
eip155Block: 0,
eip158Block: 0,
ethash: {},
homesteadBlock: 0,
neweoscBlock: 150000
},
difficulty: 524598190527327300,
genesis: «0xee8d34684cb1b1047a4bd326c43db0c85af8ffa82e9f54b6d557b4ad4eeb9135»,
head: «0xc4fa3549432703b807a826683a849fde5f79b9d1b21111992a8913ba9497a067»,
network: 20
}
}
}
«`