HTTP(s) Test Script Recorder uses User Defined Variables in alphabetical descending sort instead UI sort order

**Anastasia** ([Bug 63631](https://bz.apache.org/bugzilla//show_bug.cgi?id=63631&redirect=false)):
steps:

1. have a web app used referer header with an address like
`http://name.site.com/name/index.php`
2. add thread Group in Jmeter
3. add a 'User Defined Variables' into thread Group
3.1 Add variables:
3.1.1 PROTOCOL: http
3.1.2 HOST: name.site.com
3.1.3 PATH: /name
4. add HTTP(S) Test Script Recorder with:
4.1 Capture into threadGroup1
4.2 Capture HTTPS headers
5 capture some actions with web app
6 Look at HTTP header Manager recorded in each request

expected result:
referer:
${PROtOCOL}://${HOST}${PATH}/

actual result:
${PROtOCOL}:/${PATH}.site.com${PATH}/

PS: if you change the name of the variable 'PATH' to 'APATH' it will work correctly.
So order in UI doesn't matter and variables ordering by alphabetical descending sort.

Severity: normal
OS: All