[PATCH 6 of 6] setup: update a comment that blamed py26 for a Windows workaround

[Matt Harbison]

# HG changeset patch
# User Matt Harbison <matt_harbison at yahoo.com>
# Date 1497664642 14400
#      Fri Jun 16 21:57:22 2017 -0400
# Node ID c0554e52f27e9f61ffeada69c9c4063112974e3c
# Parent  5fc314f5aff7a649dce7fdc6ce5f817bd0c2fd67
setup: update a comment that blamed py26 for a Windows workaround

diff --git a/setup.py b/setup.py
--- a/setup.py
+++ b/setup.py
@@ -176,9 +176,8 @@
 if 'LD_LIBRARY_PATH' in os.environ:
     env['LD_LIBRARY_PATH'] = os.environ['LD_LIBRARY_PATH']
 if 'SystemRoot' in os.environ:
-    # Copy SystemRoot into the custom environment for Python 2.6
-    # under Windows. Otherwise, the subprocess will fail with
-    # error 0xc0150004. See: http://bugs.python.org/issue3440
+    # SystemRoot is required by Windows to load various DLLs.  See:
+    # https://bugs.python.org/issue13524#msg148850
     env['SystemRoot'] = os.environ['SystemRoot']
 
 if os.path.isdir('.hg'):