Fix `gcb` alias in Fish

[Cellane]

Check list

• [x] I have performed a self-review of my code
• [x] I have commented my code in hard-to-understand areas
• [x] I have made corresponding changes to the documentation

Description

When defining a custom alias for the gcb (Git checkout branch) in alias, the custom alias is not registered; rather, fish will omit the following warning on start: alias: Body cannot be empty.

I think this is caused due to a typo between the variable that’s being tested for presence and the variable that’s later used for setting the alias.

Type of change

• [x] Bug fix
• [ ] New feature
• [ ] Refactor
• [ ] Breaking change
• [ ] Documentation change

Test environment

• Shell
  • [ ] bash
  • [ ] zsh
  • [x] fish
• OS
  • [ ] Linux
  • [x] Mac OS X
  • [ ] Windows
  • [ ] Others:

[cjappl]

Thanks so much for catching this, and submitting a fix! :)