Remove trailing whitespace.
diff --git a/Doc/library/webbrowser.rst b/Doc/library/webbrowser.rst
index d340b8a..4d819e6 100644
--- a/Doc/library/webbrowser.rst
+++ b/Doc/library/webbrowser.rst
@@ -160,7 +160,7 @@
 
    url = 'http://www.python.org'
 
-   # Open URL in a new tab, if a browser window is already open. 
+   # Open URL in a new tab, if a browser window is already open.
    webbrowser.open_new_tab(url + '/doc')
 
    # Open URL in new window, raising the window if possible.