The gettext library is under LGPL 2.1, not 2.0.
* gettext-runtime/m4/intl.m4: Fix comments regarding the gettext library.
* gettext-runtime/m4/intlmacosx.m4: Likewise.
* gettext-runtime/m4/nls.m4: Likewise.
* gettext-runtime/m4/po.m4: Likewise.
* gettext-runtime/m4/progtest.m4: Likewise.
