Random.date(): fix incorrect date in range.

Correction for c505b03 commit.

Addressed to #764

Author: php-coder

src/test/java/ru/mystamps/web/tests/Random.java

@@ -76,7 +76,7 @@ public static Date date() {
 		try {
 
 			SimpleDateFormat fmt = new SimpleDateFormat("yyyy-MM-dd");
-			return between(fmt.parse("2017-01-01"), fmt.parse("2017-21-20")).date();
+			return between(fmt.parse("2017-01-01"), fmt.parse("2017-12-20")).date();
 
 		} catch (ParseException e) {
 			throw new RuntimeException(e);