Fix the transient refleaks in test_zipimport_support.
Diagnosis and original patch by Florent Xicluna (flox).
diff --git a/Lib/test/script_helper.py b/Lib/test/script_helper.py
index af5252c..f291430 100644
--- a/Lib/test/script_helper.py
+++ b/Lib/test/script_helper.py
@@ -30,7 +30,8 @@
     data = p.stdout.read()
     p.stdout.close()
     # try to cleanup the child so we don't appear to leak when running
-    # with regrtest -R.  This should be a no-op on Windows.
+    # with regrtest -R.
+    p.wait()
     subprocess._cleanup()
     return data