config_vars.sh does not handle complex passwords

[descensus]

ERROR! We were unable to read either as JSON nor YAML, these are the errors we got from each:
JSON: Expecting value: line 1 column 1 (char 0)

Syntax Error while loading YAML.
found character that cannot start any token

The error appears to be in '/opt/ascender-install/custom.config.yml': line 55, column 24, but may
be elsewhere in the file depending on the exact syntax problem.

The offending line appears to be:

# Admin password for Ledger (the username is admin by default)
LEDGER_ADMIN_PASSWORD: @vp$QT3ib~bAfh2fPeHwN
^ here

This works fine though:
LEDGER_ADMIN_PASSWORD: "@vp$QT3ib~bAfh2fPeHwN"

So it would be a good idea to have the config_vars.sh script encapsulate the passwords within quotes or similar.