user-manual: typo fix

Oops

Signed-off-by: "J. Bruce Fields" <bfields@citi.umich.edu>
diff --git a/Documentation/user-manual.txt b/Documentation/user-manual.txt
index ce0e91b..1eab4ac 100644
--- a/Documentation/user-manual.txt
+++ b/Documentation/user-manual.txt
@@ -1406,7 +1406,7 @@
 when run without any options), it is not safe to prune while other git
 operations are in progress in the same repository.
 
-For more about dangling merges, see <<dangling-merges>>.
+For more about dangling objects, see <<dangling-objects>>.
 
 
 Recovering lost changes