RestClientEmscripten: Fix UB in GET/SET

[frankosterfeld]

Do not take address of temporary.

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Comparison is base (57f31a1) 57.15% compared to head (63db429) 57.15%.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #339 +/- ## ======================================= Coverage 57.15% 57.15% ======================================= Files 69 69 Lines 7310 7310 Branches 2703 2703 ======================================= Hits 4178 4178 Misses 1322 1322 Partials 1810 1810 ```

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[sonarcloud[bot]]

Quality Gate passed

Kudos, no new issues were introduced!

0 New issues
0 Security Hotspots
No data about Coverage
0.0% Duplication on New Code

See analysis details on SonarCloud