Bug 785259: Fix override bit masking, r=bsmith, sr=honzab

--HG--
extra : rebase_source : 42bef348ffad84d9c49181c896dd0a1446a86e68

security/manager/ssl/src/SSLServerCertVerification.cpp

@@ -321,7 +321,7 @@ CertErrorRunnable::CheckCertOverrides()
       if (NS_SUCCEEDED(nsrv) && haveOverride) 
       {
        // remove the errors that are already overriden
-        remaining_display_errors -= overrideBits;
+        remaining_display_errors &= !overrideBits;
       }
     }