attempt to fix travis compilation.

src/editor/palette/location_palette.cpp

@@ -365,6 +365,8 @@ std::vector<std::string> location_palette::action_pressed() const
 	}
 	return res;
 }
-
+location_palette::~location_palette() 
+{
+}
 
 } // end namespace editor

src/editor/palette/location_palette.hpp

@@ -72,7 +72,7 @@ public:
 
 	virtual void select_item(const std::string& item_id);
 	virtual std::vector<std::string> action_pressed() const override;
-
+	~location_palette();
 private:
 
 	/** Scroll the editor-palette to the top. */