SyncNode as the xDai bridge validator

Consider to add SyncNode's account 0xfe24Cfb2F8872e9ed097C451dE065A9F6048915b to the xDai bridge validators set. This action is aimed to increase security of the bridge operations.

SyncNode is already the xDai network validator and also participates in the xDai Bridge governance Gnosis Safe.

After adding SyncNode's account to the xDai bridge validators set, 3 of 5 confirmations from the validators are required to execute transfers Dai<->xDai through the xDai TokenBridge.

The corresponding transactions have been initiated in the governance Gnosis Safes:

• Safe on the Ethereum Mainnet: https://gnosis-safe.io/app/#/safes/0x42F38ec5A75acCEc50054671233dfAC9C0E7A3F6/transactions
• Safe on the xDai chain: https://xdai.gnosis-safe.io/app/#/safes/0x7a48Dac683DA91e4faa5aB13D91AB5fd170875bd/transactions

This proposal is created mainly to expose the decision that needs to be made by the xDai bridge governors. It means that even there is no vote for this proposal here, the governors could still provide their agreements through the confirmations in the Gnosis Safes.