Fix typo in docs, replaces #2898

docs/peewee/query_operators.rst

@@ -117,7 +117,7 @@ complex.
  * Use ``|`` instead of ``or``
  * Use ``~`` instead of ``not``
  * Use ``.is_null()`` instead of ``is None`` or ``== None``.
- * Use ``== `` and ``!=`` for comparing against ``True`` and ``False``, or
+ * Use ``==`` and ``!=`` for comparing against ``True`` and ``False``, or
  you may use the implicit value of the expression.
  * **Don't forget to wrap your comparisons in parentheses when using logical operators.**