Sanity check before python script execution

Only generate Augeas ups.conf lens if we can import required Python
modules (re,glob,codecs)

Fossil-ID: SVN r3481

autogen.sh

@@ -6,7 +6,7 @@
 # re-generate files needed by configure, and created otherwise at 'dist' time
 if [ ! -f scripts/augeas/nutupsconf.aug.in ]
 then
-	if python -c pass; then
+	if python -c "import re,glob,codecs"; then
 		echo "Regenerating Augeas ups.conf lens..."
 		cd scripts/augeas && ./gen-nutupsconf-aug.py && cd ../..
 	else

scripts/augeas/Makefile.am

@@ -5,7 +5,7 @@ EXTRA_DIST = gen-nutupsconf-aug.py nutupsconf.aug.tpl \
 # only call the script to generate Augeas ups.conf lens upon "make dist",
 # and if Python is present
 dist-hook:
-	@if python -c pass; then \
+	@if python -c "import re,glob,codecs"; then \
 		echo "Regenerating Augeas ups.conf lens."; \
 		$(distdir)/gen-nutupsconf-aug.py $(distdir)/; \
 	else \