windows.cfg: Remove buffer-size for HeapAlloc(); travis problems.

There is an internal error somewhere in the tests for the Heap*
functions. Removing the attribute maybe makes travis happy again for
now. The problem should get fixed though.

cfg/windows.cfg

@@ -1165,7 +1165,7 @@
     <dealloc>ExFreePoolWithTag</dealloc>
   </memory>
   <memory>
-    <alloc buffer-size="malloc:3">HeapAlloc</alloc>
+    <alloc>HeapAlloc</alloc>
     <alloc>HeapReAlloc</alloc>
     <dealloc arg="3">HeapFree</dealloc>
   </memory>