fix error on musl:

> dcigettext.c:154:7: error: conflicting types for 'getcwd'; have 'char *(void)'
>   154 | char *getcwd ();
>       |       ^~~~~~

diff --git a/intl/dcigettext.c b/intl/dcigettext.c
index 35238e2..1d027bb 100644
--- a/intl/dcigettext.c
+++ b/intl/dcigettext.c
@@ -151,7 +151,7 @@ char *getwd ();
 #  if VMS
 #   define getcwd(buf, max) (getcwd) (buf, max, 0)
 #  else
-char *getcwd ();
+char *getcwd (char *, size_t);
 #  endif
 # endif
 # ifndef HAVE_STPCPY