ci: fix PHP CS Fixer errors

Author: ovx

.php-cs-fixer.dist.php

@@ -12,8 +12,8 @@
     // @see https://github.com/PHP-CS-Fixer/PHP-CS-Fixer/pull/7777
     ->setParallelConfig(ParallelConfigFactory::detect())
     ->setRules([
-        '@PHP71Migration' => true,
-        '@PHPUnit75Migration:risky' => true,
+        '@PHP7x1Migration' => true,
+        '@PHPUnit7x5Migration:risky' => true,
         '@Symfony' => true,
         '@Symfony:risky' => true,
         'protected_to_private' => false,

src/Altcha.php

@@ -178,7 +178,7 @@ public function verifyFieldsHash(array $formData, array $fields, string $fieldsH
         $lines = [];
         foreach ($fields as $field) {
             $value = $formData[$field] ?? '';
-            $lines[] = is_scalar($value) ? (string) $value : '';
+            $lines[] = \is_scalar($value) ? (string) $value : '';
         }
         $joinedData = implode("\n", $lines);
         $computedHash = $this->hasher->hashHex($algorithm, $joinedData);