git : remove unused git_tag function.

.README.md

@@ -501,7 +501,6 @@ Command|Description
 
 Command|Description
 ---|---
-`git_tag`|Print git tag.
 `gps`|Git push.
 `gpsf`|Git push --force.
 `gpl`|Git pull.

.linux/bash/module/git.sh

@@ -17,12 +17,6 @@ alias gi="git ls-files -ci --exclude-standard -z | xargs -0 git rm --cached"
 alias gpc="git diff >"
 alias gp="git apply"
 
-# get current git tag.
-git_tag()
-{
-  git log | grep commit -m1 | sed -e "s/.*\ //g" | cut -c 1-11;
-}
-
 # alias to preview diff while adding. adds current dir by default.
 # usage: ga [FILES]
 ga()