another improvement

Pilz.Net/Api/ApiServer.cs

@@ -280,31 +280,27 @@ public class ApiServer : IApiServer
         if (AllowMultipleRequests)
             Receive();
 
-        // Cancel if we don't have a context
-        if (context is null)
-        {
-            FreeSlot();
-            return;
-        }
-
         // Check context
-        Log.Info("Request retrived for " + context.Request.RawUrl);
-        OnCheckContext?.Invoke(this, new(context));
         var success = false;
-        try
+        if (context is not null)
         {
-            CheckContext(context);
-            success = true;
-        }
-        catch (Exception ex)
-        {
-            Log.Error("Error checking context", ex);
-            if (DebugMode)
-                throw;
-        }
-        finally
-        {
-            OnCheckContextCompleted?.Invoke(this, new(context));
+            Log.Info("Request retrived for " + context.Request.RawUrl);
+            OnCheckContext?.Invoke(this, new(context));
+            try
+            {
+                CheckContext(context);
+                success = true;
+            }
+            catch (Exception ex)
+            {
+                Log.Error("Error checking context", ex);
+                if (DebugMode)
+                    throw;
+            }
+            finally
+            {
+                OnCheckContextCompleted?.Invoke(this, new(context));
+            }
         }
 
         // Try closing the request on fail
@@ -312,7 +308,7 @@ public class ApiServer : IApiServer
         {
             try
             {
-                context.Response.Close();
+                context?.Response.Close();
             }
             catch (Exception)
             {