Fixed typo in docstring

Author: Zkaij

Lib/json/encoder.py

@@ -118,7 +118,7 @@ def __init__(self, *, skipkeys=False, ensure_ascii=True,
 
         If check_circular is true, then lists, dicts, and custom encoded
         objects will be checked for circular references during encoding to
-        prevent an infinite recursion (which would cause an RecursionError).
+        prevent an infinite recursion (which would cause a RecursionError).
         Otherwise, no such check takes place.
 
         If allow_nan is true, then NaN, Infinity, and -Infinity will be