THRIFT-4717: fix up make clean with autoconf
diff --git a/test/rs/Makefile.am b/test/rs/Makefile.am
index 54905b4..4b061ea 100644
--- a/test/rs/Makefile.am
+++ b/test/rs/Makefile.am
@@ -34,7 +34,7 @@
 
 EXTRA_DIST = \
 	Cargo.toml \
-        src/lib.rs \
+	src/lib.rs \
 	src/bin/test_server.rs \
 	src/bin/test_client.rs