message: core: add missing include
diff: @@ -19,6 +19,7 @@ void PluginImplBase::set_parent(DeviceImpl *parent)
  #ifdef __GNUG__ // GNU C++ compiler
  #include <cxxabi.h>
  #include <stdlib.h>
  +#include <string>
  std::string demangle(const char *mangled_name)
  {
  std::string result;
  @@ -34,6 +35,7 @@ std::string demangle(const char *mangled_name)
  return result;
  }
  #else
  +#include <string>
  std::string demangle(const char *name)
  {
  return name;
  