LTO saves ~4K in Flash and ~300 Bytes in RAM
Disable LTO
```
Memory region Used Size Region Size %age Used
RAM: 12256 B 16 KB 74.80%
FLASH: 84304 B 118 KB 69.77%
```
Enable LTO
```
[82/82] Linking C executable f4hwn.fusion.elf
Memory region Used Size Region Size %age Used
RAM: 11904 B 16 KB 72.66%
FLASH: 80820 B 118 KB 66.89%
```
Also fix build on Windows message:
```
docker: Error response from daemon: the working directory 'C:/Program Files/Git/src' is invalid, it needs to be an absolute path
```
Meng Zhuo