fix compilation error due to invalid stpcpy() prototype
https://bugs.gentoo.org/216588

--- a2ps-4.14/lib/xstrrpl.c
+++ a2ps-4.14/lib/xstrrpl.c
@@ -22,8 +22,6 @@
 #include <assert.h>
 #include "xstrrpl.h"
 
-extern char * stpcpy();
-
 /* Perform subsitutions in string.  Result is malloc'd
    E.g., result = xstrrrpl ("1234", subst) gives result = "112333"
    where subst = { {"1", "11"}, {"3", "333"}, { "4", ""}}