artifacts-tar: respect NO_GETTEXT

We obviously do not want to bundle `.mo` files during `make
artifacts-tar NO_GETTEXT`, but that was the case.

To fix that, go a step beyond just fixing the symptom, and simply
define the lists of `.po` and `.mo` files as empty if `NO_GETTEXT` is
set.

Helped-by: Matthias Aßhauer <[email protected]>
Signed-off-by: Johannes Schindelin <[email protected]>

Author: dscho

Makefile

@@ -2675,10 +2675,13 @@ po/git.pot: $(GENERATED_H) FORCE
 .PHONY: pot
 pot: po/git.pot
 
+ifdef NO_GETTEXT
+POFILES :=
+MOFILES :=
+else
 POFILES := $(wildcard po/*.po)
 MOFILES := $(patsubst po/%.po,po/build/locale/%/LC_MESSAGES/git.mo,$(POFILES))
 
-ifndef NO_GETTEXT
 all:: $(MOFILES)
 endif