Remove textboxwrap() and wrap() return value

This removes Graphics::textboxwrap(), as it is now an unused function.
Additionally, this removes the return value of textboxclass::wrap(), as
it is also now unused.

desktop_version/src/Textbox.h

@@ -97,7 +97,7 @@ public:
 
     void centertext(void);
 
-    int wrap(int pad);
+    void wrap(int pad);
 
     void copyoriginaltext(void);