`IndexOutOfBoundsException` in `ThousandsSeparatorTextWatcher`

[lognaturel]

This doesn't bring the full app down but likely leads to bad behavior. From analytics (needs auth):

Non-fatal Exception: java.lang.IndexOutOfBoundsException
setSpan (-1 ... -1) starts before 0
android.text.SpannableStringBuilder.checkRange (SpannableStringBuilder.java:1340)
android.widget.EditText.setSelection (EditText.java:156)
org.odk.collect.android.listeners.ThousandsSeparatorTextWatcher.afterTextChanged (ThousandsSeparatorTextWatcher.java:58)
android.widget.TextView.sendAfterTextChanged (TextView.java:11652)
com.android.internal.os.ZygoteInit.main (ZygoteInit.java:1100)