Merge branch 'js/completion-ctags-pattern-substitution-fix' into maint

The code that reads from the ctags file in the completion script
(in contrib/) did not spell ${param/pattern/string} substitution
correctly, which happened to work with bash but not with zsh.

* js/completion-ctags-pattern-substitution-fix:
  contrib/completion: escape the forward slash in __git_match_ctag

diff --cc contrib/completion/git-completion.bash
Simple merge