Fix idlelib typos discovered by min ho, pr 15018. (GH-15029)

diff --git a/Lib/idlelib/history.py b/Lib/idlelib/history.py
index 56f53a0..ad44a96 100644
--- a/Lib/idlelib/history.py
+++ b/Lib/idlelib/history.py
@@ -39,7 +39,7 @@
         return "break"
 
     def fetch(self, reverse):
-        '''Fetch statememt and replace current line in text widget.
+        '''Fetch statement and replace current line in text widget.
 
         Set prefix and pointer as needed for successive fetches.
         Reset them to None, None when returning to the start line.