fix(sigv4): UTC strftime date format (%Y%m%d%H%M%S)

app/src/media.go

@@ -57,8 +57,9 @@ func signGet(endpoint, bucket, key, secret, name string, now time.Time) SignedGe
 	const region = "garage"   // s3_region
 	const service = "s3"
 
-	date := now.Format("YYYYMMDD")
-	tstamp := now.Format("HHmmss")
+	utc := now.UTC()
+	date := utc.Format("%Y%m%d")
+	tstamp := utc.Format("%H%M%S")
 	amzDate := date + "T" + tstamp + "Z"
 
 	host := endpoint