adding attaching constructor

src/message.cc

@@ -28,6 +28,12 @@ namespace pEp {
             _filename = second._filename;
         }
 
+        Message::Blob::Blob(bloblist_t *bl)
+        {
+            _value = NULL;
+            attach(bl);
+        }
+
         Message::Blob::~Blob()
         {
             free(_value);

src/message.hh

@@ -19,6 +19,7 @@ namespace pEp {
             public:
                 Blob(char *value = NULL, size_t size = 0, string mime_type = "",
                         string filename = "");
+                Blob(bloblist_t *bl);
                 Blob(const Blob& second, bool copy = false);
                 ~Blob();
                 void attach(bloblist_t *blob);