Issue #22186: Fix typos in Lib/.

Patch by FĂ©vry Thibault.
diff --git a/Lib/poplib.py b/Lib/poplib.py
index 23a3517..2b0e3d5 100644
--- a/Lib/poplib.py
+++ b/Lib/poplib.py
@@ -41,7 +41,7 @@
 CRLF = CR+LF
 
 # maximal line length when calling readline(). This is to prevent
-# reading arbitrary lenght lines. RFC 1939 limits POP3 line length to
+# reading arbitrary length lines. RFC 1939 limits POP3 line length to
 # 512 characters, including CRLF. We have selected 2048 just to be on
 # the safe side.
 _MAXLINE = 2048