pragma once and minor change in transactions

src/serializer/serializer.hpp

@@ -16,8 +16,7 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef LMDBAL_SERIALIZER_HPP
-#define LMDBAL_SERIALIZER_HPP
+#pragma once
 
 #include "serializer.h"
 
@@ -159,5 +158,3 @@ MDB_val LMDBAL::Serializer<T>::getData() {
 
     return val;
 }
-
-#endif //LMDBAL_SERIALIZER_HPP