crashes when sending ton to Upper cased ton dns name (.ton and .t.me ) with encrypted comment

steps to reproduce:
1. go to Send
2. Enter any ton dns name with **Upper case** for example: `Boss.ton`
3. Enter any amount
4. Enter any text comment and press "Encrypt comment"
5. click Continue then app immediately crashes and exit. 

this is happening in Android latest build 5.4 and happened in 5.2.2 as well. 