Change LV month names to nominative (was genitive).

Genitive is sometimes used in long date formats, but should not be used in
date selectors for example.

http://unicode.org/cldr/trac/browser/trunk/common/main/lv.xml#L1344
Merge pull request #483 from zaadjis/master

Change LV month names to nominative (was genitive).

Latvian.