Clean by removing bin.v2, not bin.v1

[SVN r36681]

configure

@@ -330,7 +330,7 @@ all: .dummy
 	echo "Not all Boost libraries built properly."
 
 clean: .dummy
-	rm -rf bin.v1
+	rm -rf bin.v2
 
 distclean: clean
 	rm -rf Makefile config.log