[TECHNICAL-SUPPORT] LPS-33071 Manually entered values as Custom Ranges can cause ArrayIndexOutOfBoundsException in Search Portlet Modified facet

Hey Tamás,

You can find more info in the comments I've added to the commit.
I have tested it on
- Firefox 19.0 Canonical version for Ubuntu
- Google Chrome 25.0.1364.97
- Internet Explorer 9.0

Please, review my changes.
Thanks,
Tibor