protocol: fix wlr layer shell reference

This makes the linkification of the doc generator work.

 protocol/river-layer-shell-v1.xml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/protocol/river-layer-shell-v1.xml b/protocol/river-layer-shell-v1.xml
index 9caaba5..ee6890f 100644
--- a/protocol/river-layer-shell-v1.xml
+++ b/protocol/river-layer-shell-v1.xml
@@ -25,7 +25,7 @@
 
   <description summary="optional layer shell support">
     This protocol allows the river-window-management-v1 window manager to
-    support the wlr-layer-shell-v1 protocol.
+    support the wlr-layer-shell-unstable-v1 protocol.
 
     The key words "must", "must not", "required", "shall", "shall not",
     "should", "should not", "recommended", "may", and "optional" in this