fix decryption of ipv6 headers (thanks Tomas Kuliavas)

contrib/decrypt_headers.php

@@ -36,14 +36,14 @@ function hex2ip($hex) {
             .hexdec(substr($hex,4,2)).'.'
             .hexdec(substr($hex,6,2));
     } elseif (strlen($hex)==32) {
-        $ret=hexdec(substr($hex,0,4)).':'
-            .hexdec(substr($hex,4,4)).':'
-            .hexdec(substr($hex,8,4)).':'
-            .hexdec(substr($hex,12,4)).':'
-            .hexdec(substr($hex,16,4)).':'
-            .hexdec(substr($hex,20,4)).':'
-            .hexdec(substr($hex,24,4)).':'
-            .hexdec(substr($hex,28,4));
+        $ret=substr($hex,0,4).':'
+            .substr($hex,4,4).':'
+            .substr($hex,8,4).':'
+            .substr($hex,12,4).':'
+            .substr($hex,16,4).':'
+            .substr($hex,20,4).':'
+            .substr($hex,24,4).':'
+            .substr($hex,28,4);
     } else {
         $ret=$hex;
     }
@@ -88,4 +88,4 @@ Check, if it is an address string: <input type="checkbox" name="ip_addr" /><br /
 <button type="submit" name="submit" value="submit">Submit</button>
 </p>
 </form>
-</body></html>
+</body></html>