node: update uiInterface whenever warnings updated

This commit introduces slight behaviour change. Previously, the
GUI status bar would be updated for most warnings, namely
UNKNOWN_NEW_RULES_ACTIVATED, CLOCK_OUT_OF_SYNC and
PRE_RELEASE_TEST_BUILD, but not for LARGE_WORK_INVALID_CHAIN
(and not for FATAL_INTERNAL_ERROR, but that is not really
meaningful).

Fix this by always updating the status bar when the warnings are
changed.

src/node/kernel_notifications.cpp

@@ -29,7 +29,6 @@ using util::ReplaceAll;
 
 static void AlertNotify(const std::string& strMessage)
 {
-    uiInterface.NotifyAlertChanged();
 #if HAVE_SYSTEM
     std::string strCmd = gArgs.GetArg("-alertnotify", "");
     if (strCmd.empty()) return;