Merge branch 'fc/zsh-completion'

Hotfix for a recent breakage.

* fc/zsh-completion:
  completion: bash: fix gitk alias regression
  completion: zsh: fix file completion regression

contrib/completion/git-completion.bash

@@ -1829,7 +1829,7 @@ _git_fsck ()
 
 _git_gitk ()
 {
-	_gitk
+	__gitk_main
 }
 
 # Lists matching symbol names from a tag (as in ctags) file.

contrib/completion/git-completion.zsh

@@ -116,6 +116,7 @@ __gitcomp_file ()
 {
 	emulate -L zsh
 
+	compset -P '*[=:]'
 	compadd -f -p "${2-}" -- ${(f)1} && _ret=0
 }