Adjust fee for RIF Relay when connecting empty wallet

[kilrau]

Adjust Network fee to include RIF Relay's fee if RBTC in connected wallet too low for claim. And it should throw a warning similiar to "Network fee changed".

[kilrau]

We just discussed this should be a green tool tip warning that shows immediately after the wallet is connected. Not a red error warning that makes you revisit fees only after pressing "Create Atomic Swap".

Text could be: Wallet doesn't contain enough RBTC, fee adjusted to include RIF Relay fee.