Make rigclass.h more C++ agnostic

include/hamlib/rigclass.h

@@ -37,11 +37,14 @@ public:
     explicit Rig(rig_model_t rig_model);
 
     virtual ~Rig();
+#if __cplusplus >= 201103L
+    Rig(const Rig&) = delete;
+    Rig& operator=(const Rig&) = delete;
+#else
+    Rig(const Rig&);
+    Rig& operator=(const Rig&);
+#endif
 
-    Rig(const Rig&) = default;
-    Rig(Rig&&) = default;
-    Rig& operator=(const Rig&) = default;
-    Rig& operator=(Rig&&) = default;
 
     const struct rig_caps *caps;