message: Don't reserve transfer space in the vault unless we're switching
  guardians (pull from postmaster)
diff: @@ -602,7 +602,7 @@ export function ItemService(
  storeReservations[store.id] = item.amount;
  // guardian-to-guardian transfer will also need space in the vault
  - if (item.owner !== 'vault' && !store.isVault) {
  + if (item.owner !== 'vault' && !store.isVault && item.owner !== store.id) {
  storeReservations.vault = item.amount;
  }
  