fix(git): fix older commits and multiple remotes

[linrongbin16]

Fix #234 .

Regression Test

Platforms

• [ ] windows
• [x] macOS
• [ ] linux

Hosts

• [x] Test on github.com.
• [ ] Test on gitlab.com.
• [ ] Test on bitbucket.org.
• [ ] Test on codeberg.org.
• [ ] Test on git.samba.org.

Functions

• [x] Use GitLink(!) to copy git link (or open in browser).
• [x] Use GitLink(!) blame to copy the /blame link (or open in browser).
• [ ] Use GitLink(!) default_branch to open the /main//master link in browser (or open in browser).
• [ ] Use GitLink(!) current_branch to open the current branch link in browser (or open in browser).
• [ ] Copy git link in a symlink directory of git repo.
• [ ] Copy git link in an un-pushed git branch, and receive an expected error.
• [ ] Copy git link in a pushed git branch but edited file, and receive a warning says the git link could be wrong.