Fix Issue13147 - Correct the Multiprocessing Pool.map_async method signature.
Remove the error_callback which is not present in 2.7. Patch by Jyrki
Pulliainen.
diff --git a/Doc/library/multiprocessing.rst b/Doc/library/multiprocessing.rst
index c0c0ae8..454700b 100644
--- a/Doc/library/multiprocessing.rst
+++ b/Doc/library/multiprocessing.rst
@@ -1602,7 +1602,7 @@
the process pool as separate tasks. The (approximate) size of these
chunks can be specified by setting *chunksize* to a positive integer.
- .. method:: map_async(func, iterable[, chunksize[, callback[, error_callback]]])
+ .. method:: map_async(func, iterable[, chunksize[, callback]])
A variant of the :meth:`.map` method which returns a result object.