fix assert I added to KeyCode

in commit 9044260c
"add some asserts to validate KeyCode values"

Change-Id: I73dc4c9ee5e4ced699d44ecdfb306a49b853f67e
Reviewed-on: https://gerrit.libreoffice.org/12180Reviewed-by: Noel Grandin <noelgrandin@gmail.com>
Tested-by: Noel Grandin <noelgrandin@gmail.com>

include/vcl/keycod.hxx

@@ -80,7 +80,7 @@ public:
 inline vcl::KeyCode::KeyCode( sal_uInt16 nKey, sal_uInt16 nModifier )
 {
     assert(nKey <= KEY_CODE);
-    assert(nModifier >= KEY_MODTYPE);
+    assert(nModifier >= 0x1000 && nModifier <= 0xf000);
     nKeyCodeAndModifiers = nKey | nModifier;
     eFunc = KeyFuncType::DONTKNOW;
 }