fix build error

if gcc -DHAVE_CONFIG_H -I. -I. -I.. -DLOCALEDIR=\"/usr/local/share/locale\" -DPIXMAPS_DIR=\"/usr/local/share/9login/pixmaps\" -DDATADIR=\"/usr/local/share\" -I/usr/include/gtk-2.0 -I/usr/lib/gtk-2.0/include -I/usr/include/atk-1.0 -I/usr/include/cairo -I/usr/include/pango-1.0 -I/usr/include/glib-2.0 -I/usr/lib/glib-2.0/include -I/usr/include/freetype2 -I/usr/include/libpng12 -g -O2 -Wall -MT 9login-bio_functions.o -MD -MP -MF ".deps/9login-bio_functions.Tpo" -c -o 9login-bio_functions.o `test -f 'bio_functions.c' || echo './'`bio_functions.c; \
then mv -f ".deps/9login-bio_functions.Tpo" ".deps/9login-bio_functions.Po"; else rm -f ".deps/9login-bio_functions.Tpo"; exit 1; fi
bio_functions.c:236: error: static declaration of 'sha1_to_string' follows non-static declaration
bio_functions.h:14: error: previous declaration of 'sha1_to_string' was here

--- a/src/bio_functions.h	Mon Aug 18 17:35:05 2008 +0200
+++ b/src/bio_functions.h	Fri Sep 05 12:35:17 2008 +0200
@@ -11,7 +11,6 @@ void abort_sensor_action(int abort_var);
 void abort_sensor_action(int abort_var);
 void raise_error (libthinkfinger_init_status init_status);
 int verify_all_slot(void);
-void sha1_to_string(const unsigned char *sha1, char *sha1_string);
 gboolean bio_token_validate_sha1(const gchar *payload, const gchar *biotoken);
 
 #endif