t7411: quote URLs

The variables may contain white spaces, so we need to quote them.
By not quoting the variables we'd end up passing multiple arguments to
git config, which doesn't fail for two arguments as value.

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t7411-submodule-config.sh

@@ -134,8 +134,8 @@ test_expect_success 'reading of local configuration' '
 			"" submodule \
 				>actual &&
 		test_cmp expect_local_path actual &&
-		git config submodule.a.url $old_a &&
-		git config submodule.submodule.url $old_submodule &&
+		git config submodule.a.url "$old_a" &&
+		git config submodule.submodule.url "$old_submodule" &&
 		git config --unset submodule.a.path c
 	)
 '