fix json api headers

Author: SniperSister

app/Http/Controllers/Api/V1/SiteController.php

@@ -48,7 +48,7 @@ public function register(SiteRequest $request): JsonResponse
         $site = new Site();
 
         $site->key = $key;
-        $site->url = $url;
+        $site->url = rtrim($url, "/");
         $site->last_seen = Carbon::now();
 
         // Fill with site info

app/RemoteSite/Connection.php

@@ -75,7 +75,7 @@ public function performExtractionRequest(array $requestData): array
     protected function performWebserviceRequest(
         HttpMethod $method,
         string $endpoint,
-        array $requestData = []
+        ?array $requestData = null
     ): array {
         $request = new Request(
             $method->name,
@@ -89,7 +89,11 @@ protected function performWebserviceRequest(
         $response = $this->performHttpRequest(
             $request,
             [
-                "json" => $requestData
+                "json" => $requestData,
+                "headers" => [
+                    "Content-Type" => "application/json",
+                    "Accept" => "application/vnd.api+json"
+                ]
             ]
         );