JSON Extractor change double slash to one slash in extracted url from response body

**Anna** ([Bug 65801](https://bz.apache.org/bugzilla//show_bug.cgi?id=65801&redirect=false)):
Used Jmeter 5.3 and 5.4.3 - on Jmeter v. 4.0 bug is not reproduce.

java version "9"
Java(TM) SE Runtime Environment (build 9+181)
Java HotSpot(TM) 64-Bit Server VM (build 9+181, mixed mode)

Case:
I'm create a test-plan with 3 https requests
After 2 request i'll get with JSON Extractor value from url parameter. This is first element of array in key = images.
This extracted parameter i'm put in endpoint for 3 http request, e.g. GET https://test-test.ru/test/test/335x335/${url}

Expected result: i have url for request with double slash - like this: GET https://test-test.ru/test/test/335x335/https://test-test.ru/m/u/abcd/1.version=3

But i can see in request url:
GET https://test-test.ru/test/test/335x335/https:/test-test.ru/m/u/abcd/1.version=3

Created attachment [jmeter.log](https://apache.github.io/jmeter-bugzilla-attachments/01/65801/38160/jmeter.log): Jmeter log-file

Severity: normal
OS: All