bug in typed flags

/home/noel/libo2/o3tl/qa/test-typed_flags.cxx:50:52:
error: invalid argument type 'typename o3tl::typed_flags<ConfigurationChangedHint>::Wrap' to unary expression
ConfigurationChangedHint nHint2  = nHint & ~(ConfigurationChangedHint::ONE | ConfigurationChangedHint::TWO);
                                                   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1 error generated.

Change-Id: Ia03e1e7d6afff0bdbb87e82ec076d5ffb820afb2

o3tl/qa/test-typed_flags.cxx

@@ -46,6 +46,9 @@ public:
 
         nHint &= ConfigurationChangedHint::ONE;
         CPPUNIT_ASSERT( bool(nHint &= ConfigurationChangedHint::ONE) );
+
+        ConfigurationChangedHint nHint2  = nHint & ~(ConfigurationChangedHint::ONE | ConfigurationChangedHint::TWO);
+
     }
 
     // Change the following lines only, if you add, remove or rename