Update system/Common.php

Co-authored-by: Michal Sniatala <michal@sniatala.pl>

Author: gr8man

system/Common.php

@@ -479,7 +479,7 @@ function esc($data, string $context = 'html', ?string $encoding = null)
             $method = $context === 'attr' ? 'escapeHtmlAttr' : 'escape' . ucfirst($context);
 
             static $escapers = [];
-            $cacheKey        = $encoding ?? 'default';
+            $cacheKey = strtolower($encoding ?? 'utf-8');
 
             if (! isset($escapers[$cacheKey])) {
                 $escapers[$cacheKey] = new Escaper($encoding);