do not set cursor position to last editing position for git commit messages

vimrc

@@ -165,7 +165,7 @@ if has("autocmd")
     " Don't do it when the position is invalid or when inside an event handler
     " (happens when dropping a file on gvim).
     autocmd BufReadPost *
-                \ if line("'\"") > 0 && line("'\"") <= line("$") |
+                \ if (bufname("%") =~ "COMMIT_EDITMSG") == 0 && line("'\"") > 0 && line("'\"") <= line("$") |
                 \   exe "normal! g`\"" |
                 \ endif