This is for consistency with system-wide gettext.h which is used by some 3rd party libs. system-wide gettext uses `#if ENABLE_NLS`, not #ifdef
git-svn-id: svn://localhost/ardour2/branches/3.0@6942 d708f5d6-7413-0410-9779-e7cbd77b26cf
git-svn-id: svn://localhost/trunk/ardour2@24 d708f5d6-7413-0410-9779-e7cbd77b26cf