show-spring-boot-version-diff.sh: shows error "join: /dev/fd/62:21: is not sorted"

```
Comparing with Spring Boot 2.0.9.RELEASE (project vs spring versions)

join: /dev/fd/62:21: is not sorted: !-- Deprecated in favour of thymeleaf-extras-springsecurity.version --	
                            assertj:	              3.14.0	->	3.9.1
                      commons-lang3:	                 3.8	->	3.7
...
Seen here: https://travis-ci.org/php-coder/mystamps/jobs/636570976