xdg-shell: Fix a typo in description

Signed-off-by: Boyan Ding <stu_dby@126.com>
diff --git a/protocol/xdg-shell.xml b/protocol/xdg-shell.xml
index 28add40..0327f40 100644
--- a/protocol/xdg-shell.xml
+++ b/protocol/xdg-shell.xml
@@ -304,7 +304,7 @@
     </enum>
 
     <event name="configure">
-      <description summary="suggest a surface chnage">
+      <description summary="suggest a surface change">
 	The configure event asks the client to resize its surface.
 
 	The width and height arguments specify a hint to the window