Remove unused function signatures in util.h

src/util.h

@@ -76,9 +76,7 @@ char *int2str (int d, int width);
 char *left_pad_str (const char *s, int indent);
 char *ltrim (char *s);
 char *regex_extract_string (const char *str, const char *regex, int max_groups, char const **err);
-char *replace_str (const char *str, const char *old, const char *new);
 char *rtrim (char *s);
-char *secs_to_str (int secs);
 char *strtoupper(char *str);
 char *substring (const char *str, int begin, int len);
 char *trim_str (char *str);
@@ -104,7 +102,6 @@ int valid_output_type (const char *filename);
 off_t file_size (const char *filename);
 size_t append_str (char **dest, const char *src);
 uint32_t djb2(const unsigned char *str);
-uint32_t ip_to_binary (const char *ip);
 uint64_t u64encode (uint32_t x, uint32_t y);
 void genstr(char *dest, size_t len);
 void set_tz (void);