Fixing exit code keybase_logged_in

[RobertYoung]

Running tfenv install 0.12.19 with keybase installed and following Hashicorp user still didn't verify Terraforms PGP signature. Upon further investigation, I noticed that keybase_logged_in had 141 exit code.

https://stackoverflow.com/a/19120674

bash-3.2$ keybase status | grep -Eq '^Logged in:[[:space:]]*yes';
bash-3.2$ echo ${PIPESTATUS[@]}
141 0

Changed the grep so it outputs the correct exit code:

bash-3.2$ grep -Eq '^Logged in:[[:space:]]*yes' <(keybase status)
bash-3.2$ echo ${PIPESTATUS[@]}
0
bash-3.2$ grep -Eq '^Logged in:[[:space:]]*no' <(keybase status)
bash-3.2$ echo ${PIPESTATUS[@]}
1