[ethereum/go-ethereum] Miner info is empty in block (#17454)

Hi!

Trying to get information about blocks. For this I use web3 methods. All information displays normaly expect miner address. Tested in rinkeby network

#### System information

Geth version: `1.8.13`
OS & Version: Linux

#### Expected behaviour
Miner address should be present in block information

#### Actual behaviour
Miner address in null `0x0000000000000000000000000000000000000000`

#### Steps to reproduce the behaviour
1. Run geth `geth —rpc —rpcaddr 0.0.0.0 —rpcvhosts * —rinkeby —syncmode «fast»`
2. Try to get information about any block, e.g.
«`
eth.getBlock(2848394)

{
difficulty: 1,
extraData: «0xd68301080d846765746886676f312e3130856c696e7578000000000000000000773ab2ca8f47904a14739ad80a75b71d9d29b9fff8b7ecdcb73efffa6f74122f17d304b5dc8e6e5f256c9474dd115c8d4dae31b7a3d409e5c3270f8fde41cd8c00»,
gasLimit: 7753377,
gasUsed: 1810195,
hash: «0x7004c895e812c55b0c2be8a46d72ca300a683dc27d1d7917ee7742d4d0359c1f»,
logsBloom: «0x00000000000000020000000000002000000400000000000000000000000000000000000000000000040000080004000020000010000000000000000000000000000000000000000008000008000000000000000000200000000000000000000000000000020000000000000000000800000000000000804000000010080000000800000000000000000000000000000000000000000000800000000000080000000008000400000000404000000000000000000000000200000000000000000000000002000000000000001002000000000000002000000008000000000020000000000000000000000000000000000000000000000000400000800000000000»,
miner: «0x0000000000000000000000000000000000000000»,
mixHash: «0x0000000000000000000000000000000000000000000000000000000000000000»,
nonce: «0x0000000000000000»,
number: 2848394,
parentHash: «0x20350fc367e19d3865be1ea7da72ab81f8f9941c43ac6bb24a34a0a7caa2f3df»,
receiptsRoot: «0x6ade4ac1079ea50cfadcce2b75ffbe4f9b14bf69b4607bbf1739463076ca6246»,
sha3Uncles: «0x1dcc4de8dec75d7aab85b567b6ccd41ad312451b948a7413f0a142fd40d49347»,
size: 6437,
stateRoot: «0x23f63347851bcd109059d007d71e19c4f5e73b7f0862bebcd04458333a004d92»,
timestamp: 1534796040,
totalDifficulty: 5353647,
transactions: [«0x7e3bb851fc74a436826d2af6b96e4db9484431811ef0d9c9e78370488d33d4e5», «0x3976fd1e3d2a715c3cfcfde9bd3210798c26c017b8edb841d319227ecb3322fb», «0xd8db124005bb8b6fda7b71fd56ac782552a66af58fe843ba3c4930423b87d1d2», «0x10c1a1ca4d9f4b2bd5b89f7bbcbbc2d69e166fe23662b8db4f6beae0f50ac9fd», «0xaa58a6545677c796a56b8bc874174c8cfd31a6c6e6ca3a87e086d4f66d52858a»],
transactionsRoot: «0xde8d25c0b9b54310128a21601331094b43f910f9f96102869c2e2dca94884bf4»,
uncles: []
}
«`

Also found that in «light» mode the same issue appears. Also in «light» mode `getTransaction` return null instead transaction info.

So, is Miner address is availible only in «full» sync mode?

Kind regards