[docs] Automatically update copyright year in libc++.

diff --git a/libcxx/docs/conf.py b/libcxx/docs/conf.py
index 5516cdb..f3c904c 100644 (file)
--- a/libcxx/docs/conf.py
+++ b/libcxx/docs/conf.py
@@ -41,7 +41,7 @@ master_doc = 'index'
 
 # General information about the project.
 project = u'libc++'
-copyright = u'2011-2021, LLVM Project' % date.today().year
+copyright = u'2011-%d, LLVM Project' % date.today().year
 
 # The version info for the project you're documenting, acts as replacement for
 # |version| and |release|, also used in various other places throughout the