HHH-17975: use the same precision (millis) for resolving revision tim…

…estamps from Instant as from LocalDateTime

hibernate-envers/src/main/java/org/hibernate/envers/internal/revisioninfo/RevisionTimestampValueResolver.java

@@ -100,7 +100,7 @@ else if ( timestampData.isInstant() ) {
 				return instant;
 			}
 			else {
-				return instant.getEpochSecond();
+				return instant.toEpochMilli();
 			}
 		}
 		return null;