change function prototype to work with c2x standard. Build fails with clang16 without this
See: https://github.com/ascii-boxes/boxes/issues/106
--- a/src/remove.h+++ b/src/remove.h@@ -22,7 +22,7 @@int remove_box();
-void output_input();+void output_input(const int trim_only);#endif /*REMOVE_H*/