Fix changes that were lost in the last revert.

Author: JF002

bootloader/bootloader-5.0.4.bin

@@ -1,8 +1,8 @@
 # Build
 ## Dependencies
 To build this project, you'll need:
- - A cross-compiler : [gcc-arm-none-eabi-8-2019-q3-update](https://developer.arm.com/tools-and-software/open-source-software/developer-tools/gnu-toolchain/gnu-rm/downloads/8-2019q3-update)
- - The NRF52 SDK 15.3.0 : [nRF5_SDK_15.3.0_59ac345](https://developer.nordicsemi.com/nRF5_SDK/nRF5_SDK_v15.x.x/nRF5_SDK_15.3.0_59ac345.zip)
+ - A cross-compiler : [ARM-GCC (9-2020-q2-update)](https://developer.arm.com/tools-and-software/open-source-software/developer-tools/gnu-toolchain/gnu-rm/downloads/9-2020-q2-update)
+ - The NRF52 SDK 15.3.0 : [nRF-SDK v15.3.0](https://developer.nordicsemi.com/nRF5_SDK/nRF5_SDK_v15.x.x/nRF5_SDK_15.3.0_59ac345.zip)
  - A reasonably recent version of CMake (I use 3.16.5)
 
 ## Build steps