How can I prevent the earphones from muting the speaker?

The FM radio in my phone uses the earphone cable as the antenna. It plays the music just fine if I plug the jack in about 2/3 the way (and only hisses without it). But if I push the jack all the way in, the phone starts outputting all the audio to the earphones and mutes the speaker. The range between "antenna OK" and "Earphones active" is about 2-3mm, and the jack is sitting completely loose, so I can't even move the phone or either the jack goes loose or the phones activate and mute the speaker. There are posts how to do it programatically: (https://stackoverflow.com/questions/20965530/how-to-mute-audio-in-headset-but-let-it-play-on-speaker-programmatically) (https://stackoverflow.com/questions/30322002/what-code-can-disable-headphone-jack-for-an-android4-4-device) - but I'm not too fond of writing my own app to do this. Is there an app to do this maybe? The phone is Xiaomi Redmi Note 2, running Android 5.0.2 if that helps. [actually, I don't really care if the earphones are still active; I just need the speaker to work]