Remove fix_name() function

With unicode support this function is not longer valid.

friendlist.h

@@ -7,6 +7,5 @@
 ToxWindow new_friendlist();
 int friendlist_onFriendAdded(Messenger *m, int num);
 void disable_chatwin(int f_num);
-void fix_name(uint8_t *name);
 
 #endif /* end of include guard: FRIENDLIST_H_53I41IM */