Fix README.md bitcoin address

README.md

@@ -2,7 +2,7 @@
 
 [![Donate](https://img.shields.io/badge/Donate-PayPal-green.svg)](https://www.paypal.com/cgi-bin/webscr?cmd=_s-xclick&hosted_button_id=JWBSYHF4SMC68)
 
-[![Donate (Bitcoin)](https://img.shields.io/badge/Donate-Bitcoin-blue.svg)](bitcoin:1E5rgzgA1sS3QH7r1ToWxRC3GEavfsGMrx)
+**mailcow Bitcoin donations:** 1E5rgzgA1sS3QH7r1ToWxRC3GEavfsGMrx
 
 Please see [the official documentation](https://mailcow.github.io/mailcow-dockerized-docs/) for instructions.