javaunohelper: fix some misspellings

Change-Id: Ibfa6e6ed2a4b4d3fa4b5e5cf624e42442653d358
Reviewed-on: https://gerrit.libreoffice.org/11363
Reviewed-by: Thomas Arnhold <thomas@arnhold.org>
Tested-by: Thomas Arnhold <thomas@arnhold.org>