wxGUI translation update for Latvian language + fixes (trunk, https://trac.osgeo.org/grass/changeset/67448 + https://trac.osgeo.org/grass/changeset/67448)

git-svn-id: https://svn.osgeo.org/grass/grass/branches/releasebranch_7_0@67450 15284696-431f-4ddb-bdfa-cd5b030d7da7