Fix ESP8266 readBytes cast.

Author: alvarolb

library.properties

@@ -1,5 +1,5 @@
 name=thinger.io
-version=2.3.0
+version=2.3.1
 author=Alvaro Luis Bustamante <[email protected]>
 maintainer=Thinger.io <[email protected]>
 sentence=Arduino library for the thinger.io IoT platform.

src/ThingerWebConfig.h

@@ -37,7 +37,7 @@ class pson_spiffs_decoder : public protoson::pson_decoder{
 
 protected:
     virtual bool read(void* buffer, size_t size){
-        file_.readBytes((uint8_t*)buffer, size);
+        file_.readBytes((char*)buffer, size);
         protoson::pson_decoder::read(buffer, size);
         return true;
     }