Update copyright note year

Author: andywer

electron-build.yml

@@ -1,7 +1,7 @@
 # Don't change the appId! See <https://www.electron.build/configuration/nsis#guid-vs-application-name>
 appId: io.solarwallet.app
 productName: Solar Wallet
-copyright: Copyright © 2020 SatoshiPay Ltd
+copyright: Copyright © 2021 SatoshiPay Ltd
 
 protocols:
   name: Stellar transaction / payment requests URL,