Tidy README license wrapping

README.md

@@ -150,5 +150,4 @@ After 3 wrong guesses, the key also needs unplugging before it accepts more.
 
 MIT; see [LICENSE](LICENSE). Firmware builds also include the Pico SDK
 (BSD-3-Clause), TinyUSB (MIT) and Mbed TLS (Apache-2.0 or GPL-2.0-or-later),
-each under its own
-license.
+each under its own license.