Fixed setHost nullable value

src/Pecee/Http/Request.php

@@ -406,7 +406,7 @@ class Request
     public function setHost(?string $host): void
     {
         // Strip any potential ports from hostname
-        if (strpos($host, ':') !== false) {
+        if (strpos((string)$host, ':') !== false) {
             $host = strstr($host, strrchr($host, ':'), true);
         }