Bugfix. Don't condirer <toolset-msvc:version>xxx to be conditional property.

[SVN r22172]

tools/build

@@ -1 +1 @@
-Subproject commit afe6803218be2abe74cbddf06b8c0a4ed1fecca1
+Subproject commit c868bc9ca0212d06b9e7e57fdadc862a78777884