Remove default for git reset (#4993)

The command will do the same as before, but now you can also specify
a path.

Example:
grh branch-name
grhh tag-name

plugins/git/git.plugin.zsh

@@ -211,8 +211,8 @@ alias grbc='git rebase --continue'
 alias grbi='git rebase -i'
 alias grbm='git rebase master'
 alias grbs='git rebase --skip'
-alias grh='git reset HEAD'
-alias grhh='git reset HEAD --hard'
+alias grh='git reset'
+alias grhh='git reset --hard'
 alias grmv='git remote rename'
 alias grrm='git remote remove'
 alias grset='git remote set-url'