BUGFIX VC9 does not support unordered_map

git-svn-id: https://assimp.svn.sourceforge.net/svnroot/assimp/trunk@1075 67173fc5-114c-0410-ac8e-9d2fd5bffc1f

code/STEPFile.h

@@ -47,7 +47,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #include <typeinfo>
 
 //
-#if _MSC_VER >= 1500 || (defined __GNUC___)
+#if _MSC_VER > 1500 || (defined __GNUC___)
 #	define ASSIMP_STEP_USE_UNORDERED_MULTIMAP
 #	else
 #	define step_unordered_map map