Cannot send sats when msat mint balance is less than 1000 msats

[sh1ftred]

Problem

When the msat mint's balance is less than 1000 msats, it's not possible to send sats.

Expected Behavior

Users should be able to send sats even when the msat mint balance is below 1000 msats.

Actual Behavior

Sending sats fails when the msat mint balance is less than 1000 msats.

Steps to Reproduce

1. Ensure msat mint balance is less than 1000 msats
2. Attempt to send sats
3. Transaction fails