PCRE2 fix for PHP 7.3+

PCRE2 is strict that the hyphen needs to be moved to the end, or escaped for this to work.

src/Bernard/Message/DefaultMessage.php

@@ -19,7 +19,7 @@ public function __construct($name, array $parameters = array())
             $this->$k = $v;
         }
 
-        $this->name = preg_replace('/(^([0-9]+))|([^[:alnum:]-_+])/i', '', $name);
+        $this->name = preg_replace('/(^([0-9]+))|([^[:alnum:]\-_+])/i', '', $name);
     }
 
     /**