maint: Revert copyright year changes in test data

maint: Revert copyright year changes in test data

Some test programs started failing after mass update of copyright notice
for year 2016 (commit 7fa0c277), because of embedded test data with
fixed copyright dates.  Revert the commit for those files.
Reported by Bruno Haible.
* .x-update-copyright: Exclude test programs embedding copyright date.
* gettext-tools/tests/msgcomm-22: Revert the last change.
* gettext-tools/tests/msgfilter-sr-latin-1: Likewise.
* gettext-tools/tests/msggrep-1: Likewise.
* gettext-tools/tests/msggrep-2: Likewise.
* gettext-tools/tests/msggrep-3: Likewise.
* gettext-tools/tests/msggrep-4: Likewise.
* gettext-tools/tests/msggrep-5: Likewise.
* gettext-tools/tests/msggrep-9: Likewise.
* gettext-tools/tests/msggrep-11: Likewise.
* gettext-tools/tests/msgmerge-14: Likewise.