Included missing header file for boost (bind/placeholders)

Author: SmartArray

src/validation.cpp

@@ -46,6 +46,7 @@
 
 #include <boost/algorithm/string/replace.hpp>
 #include <boost/thread.hpp>
+#include <boost/bind.hpp>
 
 #if defined(NDEBUG)
 # error "DigiByte cannot be compiled without assertions."

src/validationinterface.cpp

@@ -17,6 +17,7 @@
 #include <atomic>
 #include <future>
 
+#include <boost/bind.hpp>
 #include <boost/signals2/signal.hpp>
 
 struct MainSignalsInstance {