Make helm-ls-git-grep-command obsolete.

Author: Thierry Volpiatto

helm-ls-git.el

@@ -67,6 +67,7 @@ Valid values are symbol 'abs (default) or 'relative."
 ;; alias it for backward compatibility.
 (defvar helm-ls-git-grep-command)
 (defvaralias 'helm-ls-git-grep-command 'helm-grep-git-grep-command)
+(make-obsolete-variable 'helm-ls-git-grep-command 'helm-grep-git-grep-command "1.8.0")
 
 (defcustom helm-ls-git-default-sources '(helm-source-ls-git-status
                                          helm-source-ls-git-buffers