Avoiding infinite loops when an error message handlers triggers errors

itself.

If an error is triggered inside one of the reporter_* handlers, the
message about that will now fall back to stderr.

src/EventHandler.cc

@@ -13,6 +13,7 @@ EventHandler::EventHandler(const char* arg_name)
 	local = 0;
 	type = 0;
 	group = 0;
+	error_handler = false;
 	enabled = true;
 	}