Issue #16714: use 'raise' exceptions, don't 'throw'.

Patch by Serhiy Storchaka.
diff --git a/Lib/multiprocessing/util.py b/Lib/multiprocessing/util.py
index 7495813..72385a8 100644
--- a/Lib/multiprocessing/util.py
+++ b/Lib/multiprocessing/util.py
@@ -290,7 +290,7 @@
 
         if current_process() is not None:
             # We check if the current process is None here because if
-            # it's None, any call to ``active_children()`` will throw
+            # it's None, any call to ``active_children()`` will raise
             # an AttributeError (active_children winds up trying to
             # get attributes from util._current_process).  One
             # situation where this can happen is if someone has