Update ConfigSetCommand.php

fix static tests failures:

```
/var/www/html/setup/src/Magento/Setup/Console/Command/ConfigSetCommand.php:76	The method execute() has a Cyclomatic Complexity of 10. The configured cyclomatic complexity threshold is 10.
```

```
FILE: ...tml/setup/src/Magento/Setup/Console/Command/ConfigSetCommand.php
----------------------------------------------------------------------
FOUND 0 ERRORS AND 2 WARNINGS AFFECTING 2 LINES
----------------------------------------------------------------------
 20 | WARNING | [ ] Class description should contain additional
    |         |     information beyond the name already supplies.
 87 | WARNING | [x] Expected 0 spaces after opening bracket; newline
    |         |     found
----------------------------------------------------------------------
PHPCBF CAN FIX THE 1 MARKED SNIFF VIOLATIONS AUTOMATICALLY
----------------------------------------------------------------------
```

Author: flancer64

setup/src/Magento/Setup/Console/Command/ConfigSetCommand.php

@@ -84,11 +84,10 @@ protected function execute(InputInterface $input, OutputInterface $output)
             $commandOptions[$option->getName()] = false;
 
             $currentValue = $this->deploymentConfig->get($option->getConfigPath());
-            if (
-                ($currentValue !== null) &&
+            $needOverwrite = ($currentValue !== null) &&
                 ($inputOptions[$option->getName()] !== null) &&
-                ($inputOptions[$option->getName()] !== $currentValue)
-            ) {
+                ($inputOptions[$option->getName()] !== $currentValue);
+            if ($needOverwrite) {
                 $dialog = $this->getHelperSet()->get('question');
                 $question = new Question(
                     '<question>Overwrite the existing configuration for ' . $option->getName() . '?[Y/n]</question>',