Windows: Fix build with SCons 4.2.0

(cherry picked from commit c191cfbddfa2f26b22f8c3edbc529342cd2fe2e2)

platform/windows/detect.py

@@ -139,7 +139,7 @@ def setup_msvc_auto(env):
     env['TARGET_ARCH'] = None
     if env['bits'] != 'default':
         env['TARGET_ARCH'] = {'32': 'x86', '64': 'x86_64'}[env['bits']]
-    if env.has_key('msvc_version'):
+    if 'msvc_version' in env:
            env['MSVC_VERSION'] = env['msvc_version']
     env.Tool('msvc')
     env.Tool('mssdk')                      # we want the MS SDK