fix: multiple alerts shown to QR reading

[tuliomir]

Multiple alerts were being shown one over the other when the user tried to scan a QR Code and an error was raised.

Acceptance Criteria

• Only one alert should be shown when an error occurs on Send Tokens

Security Checklist

• Make sure you do not include new dependencies in the project unless strictly necessary and do not include dev-dependencies as production ones. More dependencies increase the possibility of one of them being hijacked and affecting us.