Move System::httpExit to BaseModule->httpExit

- This will ensure headers set in BaseModule->run will be carried in httpExit scenarios
- Deprecate httpExit() method in Core\System

src/Module/PermissionTooltip.php

@@ -166,9 +166,9 @@ class PermissionTooltip extends \Friendica\BaseModule
 		}
 
 		if (!empty($l)) {
-			System::httpExit($o . implode(', ', $l));
+			$this->httpExit($o . implode(', ', $l));
 		} else {
-			System::httpExit($o . $receivers);;
+			$this->httpExit($o . $receivers);;
 		}
 	}