Unterminated tie with tuplets

[Jimmie Felidae]

Hello List,

I got a warning of unterminated tie. The warning message is:

```
/tmp/frescobaldi-k7Gcla/tmpqo6ujA/document.ly:3:2: warning: unterminated tie
  c''2.~  \times 2/3 {a'4 g'8~} | g'2 r2|
```

Related tiny example:

```
\version "2.14.0"
{
  c''2.~  \times 2/3 {a'4 g'8~} | g'2 r2|
}
```

If anyone understands why it happens, please let me know !

Thanks,
Jimmie