Never expect the replica iterators to be sorted (#538)

cmd/litestream/generations.go

@@ -5,6 +5,7 @@ import (
 	"flag"
 	"fmt"
 	"os"
+	"sort"
 	"text/tabwriter"
 	"time"
 
@@ -90,6 +91,8 @@ func (c *GenerationsCommand) Run(ctx context.Context, args []string) (err error)
 			continue
 		}
 
+		sort.Strings(generations)
+
 		// Iterate over each generation for the replica.
 		for _, generation := range generations {
 			createdAt, updatedAt, err := r.GenerationTimeBounds(ctx, generation)