Bug#903373: "not a valid UTF-8 string" errors creating compose table in en_IN locale

[Avinash Sonawane <rootkea@gmail.com>]

I'm getting these exact errors on weston.

```
$ weston
...
xkbcommon: ERROR: /usr/share/X11/locale/iso8859-1/Compose:39:34:
string literal is not a valid UTF-8 string
xkbcommon: ERROR: /usr/share/X11/locale/iso8859-1/Compose:40:29:
string literal is not a valid UTF-8 string
xkbcommon: ERROR: /usr/share/X11/locale/iso8859-1/Compose:41:29:
string literal is not a valid UTF-8 string
xkbcommon: ERROR: /usr/share/X11/locale/iso8859-1/Compose:42:29:
string literal is not a valid UTF-8 string
xkbcommon: ERROR: /usr/share/X11/locale/iso8859-1/Compose:43:29:
string literal is not a valid UTF-8 string
xkbcommon: ERROR: /usr/share/X11/locale/iso8859-1/Compose:44:27:
string literal is not a valid UTF-8 string
xkbcommon: ERROR: /usr/share/X11/locale/iso8859-1/Compose:45:27:
string literal is not a valid UTF-8 string
xkbcommon: ERROR: /usr/share/X11/locale/iso8859-1/Compose:46:27:
string literal is not a valid UTF-8 string
xkbcommon: ERROR: /usr/share/X11/locale/iso8859-1/Compose:47:27:
string literal is not a valid UTF-8 string
xkbcommon: ERROR: /usr/share/X11/locale/iso8859-1/Compose:48:29:
string literal is not a valid UTF-8 string
xkbcommon: ERROR: /usr/share/X11/locale/iso8859-1/Compose:49:29:
string literal is not a valid UTF-8 string
xkbcommon: ERROR: /usr/share/X11/locale/iso8859-1/Compose:49:29: too many errors
xkbcommon: ERROR: /usr/share/X11/locale/iso8859-1/Compose:49:29:
failed to parse file
could not create XKB compose table for locale 'en_IN'.  Disabiling compose
```

Thanks!