Fix code example by adding a missing import.

Fixes #1557890.

Backported from trunk.

diff --git a/Doc/lib/libctypes.tex b/Doc/lib/libctypes.tex
index 2bae25b99067099555b10f4cb46f18cb69d86356..8474a44ef00715c076ada48aa369b06269fcf881 100755 (executable)
--- a/Doc/lib/libctypes.tex
+++ b/Doc/lib/libctypes.tex
@@ -1848,7 +1848,7 @@ GetWindowRect(
 
 Here is the wrapping with \code{ctypes}:
 \begin{quote}
-\begin{verbatim}>>> from ctypes import POINTER, WINFUNCTYPE, windll
+\begin{verbatim}>>> from ctypes import POINTER, WINFUNCTYPE, windll, WinError
 >>> from ctypes.wintypes import BOOL, HWND, RECT
 >>> prototype = WINFUNCTYPE(BOOL, HWND, POINTER(RECT))
 >>> paramflags = (1, "hwnd"), (2, "lprect")