WIP: Fixup debian building for solokey hacker

[craigcomstock]

No description provided.

[craigcomstock]

@merlokk now stuck at

craig@other:~/src/solokeys-openpgp$ make
g++ -std=c++17 -Os -Wall -g3 -I. -Ipc/ -Isrc/ -Ilibs/mbedtls/ -Ilibs/mbedtls/mbedtls/crypto/include/ -Ilibs/stm32fs/ -Ilibs/bearssl/ -c -o obj/cryptolib.o ./src/cryptolib.cpp
./src/cryptolib.cpp:23:10: fatal error: salty.h: No such file or directory
 #include "salty.h"
          ^~~~~~~~~
compilation terminated.
make: *** [Makefile:27: obj/cryptolib.o] Error 1

[craigcomstock]

My goal here was building for solo hacker key. Turns out a PR for this is in progress here: solokeys/solo1#447 and should be used instead of building JUST this openpgp repo. Thanks.