To resolve RLN build issues like this:
```
Building: librln_v0.3.4.a
./scripts/build_rln.sh: line 29: rustup: command not found
Warning: to ensure you are building in a supported repo state, please always run "make update" after "git pull"
(it looks like you've forgotten to do this).
This also applies whenever you switch to a new branch or commit, e.g.: whenever you run "git checkout ...".
Failed to download -rln.tar.gz
./scripts/build_rln.sh: line 42: jq: command not found
error: could not find `Cargo.toml` in `/app` or any parent directory
make: *** [Makefile:131: librln_v0.3.4.a] Error 127
```
Signed-off-by: Jakub Sokołowski <jakub@status.im>