Properly remove trailing spaces

Author: terryjreedy

Doc/library/stdtypes.rst

@@ -4825,7 +4825,7 @@ can be used interchangeably to index the same dictionary entry.
 
    Providing keyword arguments as in the first example only works for keys that
    are valid Python identifiers.  Otherwise, any valid keys can be used.
-   
+
    Dictionaries compare equal if and only if they have the same ``(key,
    value)`` pairs (regardless of ordering). Order comparisons ('<', '<=', '>=', '>') raise
    :exc:`TypeError`.  To illustrate dictionary creation and equality,