Account for server window changes when discarding data frames

If streams are cancelled, this might result in hanging connections, because the client thinks the server window is still large enough and doesn't increase it.

src/Connection/Internal/Http2ConnectionProcessor.php

@@ -798,6 +798,12 @@ public function handleConnectionException(Http2ConnectionException $exception):
 
     public function handleData(int $streamId, string $data): void
     {
+        $length = \strlen($data);
+
+        $this->serverWindow -= $length;
+
+        $this->increaseConnectionWindow();
+
         if (!isset($this->streams[$streamId])) {
             return;
         }
@@ -815,9 +821,6 @@ public function handleData(int $streamId, string $data): void
             return;
         }
 
-        $length = \strlen($data);
-
-        $this->serverWindow -= $length;
         $stream->serverWindow -= $length;
         $stream->received += $length;
 
@@ -841,8 +844,6 @@ public function handleData(int $streamId, string $data): void
             return;
         }
 
-        $this->increaseConnectionWindow();
-
         $promise = $stream->body->emit($data);
         $promise->onResolve(function (?\Throwable $exception) use ($streamId): void {
             if ($exception || !isset($this->streams[$streamId])) {