fixup! implementing decoder interface

Author: andreagilardoni

src/cbor/CborDecoder.h

@@ -36,8 +36,6 @@ class CBORMessageDecoderInterface {
 class CBORMessageDecoderClass: public Decoder {
 public:
   static CBORMessageDecoderClass& getInstance() {
-    static CBORMessageDecoderClass singleton;
-
     return singleton;
   }
 
@@ -49,6 +47,7 @@ class CBORMessageDecoderClass: public Decoder {
   Decoder::Status decode(Message* msg, const uint8_t* const buf, size_t &len);
 private:
   std::map<CBORTag, CBORMessageDecoderInterface*> decoders;
+  static CBORMessageDecoderClass singleton;
 };
 
 extern CBORMessageDecoderClass& CBORMessageDecoder;