mscoree: Better support RUNTIME_INFO_UPGRADE_VERSION in, GetRequestedRuntimeInfo (try 3)

[Vincent Povirk]

-    FIXME("Unrecognized version %s\n", debugstr_w(pwzVersion));
+    WARN("Unrecognized version %s\n", debugstr_w(pwzVersion));

I'm not so sure about this. I think GetRuntime is still incomplete, so
I'd still like to know when it fails. You will get a useless FIXME in
the case where RUNTIME_INFO_UPGRADE_VERSION is specified, but I think
a program that makes that specifies a version number and that flag is
doing it wrong. Anyway, we shouldn't be spammed with fixme's, right?