etags: force Python as a language

etags has cannot properly identify the scripts/gnt-* files as Python, so
we statically force the language to Python.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Michael Hanselmann <hansmi@google.com>

Makefile.am

@@ -684,7 +684,7 @@ TAGS: $(BUILT_SOURCES)
 	find . -path './lib/*.py' -o -path './scripts/gnt-*' -o \
 	  -path './daemons/ganeti-*' -o -path './tools/*' -o \
 	  -path './qa/*.py' | \
-	  etags -
+	  etags -l python -
 
 .PHONY: coverage
 coverage: $(BUILT_SOURCES) $(python_tests)