menudata.py needs the installed menudata.xml, not the source file

git-svn-id: https://svn.osgeo.org/grass/grass/trunk@40832 15284696-431f-4ddb-bdfa-cd5b030d7da7

gui/wxpython/Makefile

@@ -21,7 +21,7 @@ default: $(DSTFILES) menustrings.py
 $(ETCDIR)/%: % | $(DSTDIRS)
 	$(INSTALL_DATA) $< $@
 
-menustrings.py: gui_modules/menudata.py xml/menudata.xml
+menustrings.py: gui_modules/menudata.py $(ETCDIR)/xml/menudata.xml
 	GISBASE="$(GISBASE)" \
 	$(PYTHON) $< > $@