fix: seed sensing_online translations

Author: cwillisf

msg/js/en.js

@@ -219,6 +219,7 @@ Blockly.Msg["SENSING_CURRENT_HOUR"] = "hour";
 Blockly.Msg["SENSING_CURRENT_MINUTE"] = "minute";
 Blockly.Msg["SENSING_CURRENT_SECOND"] = "second";
 Blockly.Msg["SENSING_DAYSSINCE2000"] = "days since 2000";
+Blockly.Msg["SENSING_ONLINE"] = "is online?";
 Blockly.Msg["SENSING_USERNAME"] = "username";
 Blockly.Msg["SENSING_USERID"] = "user id";
 Blockly.Msg["SOUND_PLAY"] = "start sound %1";