refactor: replace Cache-control with Cache-Control

Author: kenjis

system/HTTP/DownloadResponse.php

@@ -227,9 +227,8 @@ public function setContentType(string $mime, string $charset = 'UTF-8')
      */
     public function noCache(): self
     {
-        $this->removeHeader('Cache-control');
-
-        $this->setHeader('Cache-control', ['private', 'no-transform', 'no-store', 'must-revalidate']);
+        $this->removeHeader('Cache-Control');
+        $this->setHeader('Cache-Control', ['private', 'no-transform', 'no-store', 'must-revalidate']);
 
         return $this;
     }

system/HTTP/ResponseTrait.php

@@ -345,8 +345,8 @@ protected function formatBody($body, string $format)
      */
     public function noCache()
     {
-        $this->removeHeader('Cache-control');
-        $this->setHeader('Cache-control', ['no-store', 'max-age=0', 'no-cache']);
+        $this->removeHeader('Cache-Control');
+        $this->setHeader('Cache-Control', ['no-store', 'max-age=0', 'no-cache']);
 
         return $this;
     }
@@ -399,7 +399,7 @@ public function setCache(array $options = [])
             unset($options['last-modified']);
         }
 
-        $this->setHeader('Cache-control', $options);
+        $this->setHeader('Cache-Control', $options);
 
         return $this;
     }