Disabled request body parsing if the handler does nothing. (#266)

* Disabled request body parsing if the handler does nothing. This will save memory and prevent crashes on large POST requests.

Signed-off-by: Alexandr Zarubkin <me21@yandex.ru>

* Marked SPIFFSEditor request handler as non-trivial, as it needs to process POST requests.

Signed-off-by: Alexandr Zarubkin <me21@yandex.ru>

src/SPIFFSEditor.h

@@ -18,6 +18,7 @@ class SPIFFSEditor: public AsyncWebHandler {
     virtual bool canHandle(AsyncWebServerRequest *request) override final;
     virtual void handleRequest(AsyncWebServerRequest *request) override final;
     virtual void handleUpload(AsyncWebServerRequest *request, const String& filename, size_t index, uint8_t *data, size_t len, bool final) override final;
+    virtual bool isRequestHandlerTrivial() override final {return false;}
 };
 
 #endif