Improve appending scheme part of the HTTP client URL

[ldclakmal]

Purpose

$subject related to ballerina-platform/ballerina-library#2816

Checklist

• Linked to an issue
• Updated the changelog
• Added tests
• Updated the spec

[codecov]

Codecov Report

Merging #572 (46bef99) into master (996fd98) will increase coverage by 0.18%.
The diff coverage is 100.00%.

@@             Coverage Diff              @@
##             master     #572      +/-   ##
============================================
+ Coverage     85.24%   85.43%   +0.18%     
- Complexity       31       36       +5     
============================================
  Files            11       11              
  Lines           705      714       +9     
  Branches        367      370       +3     
============================================
+ Hits            601      610       +9     
  Misses           97       97              
  Partials          7        7              

Impacted Files	Coverage Δ
...ain/java/io/ballerina/stdlib/jwt/JwtConstants.java	100.00% <ø> (ø)
.../main/java/io/ballerina/stdlib/jwt/JwksClient.java	82.03% <100.00%> (+1.35%)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 3274d14...46bef99. Read the comment docs.