Merge branch 'vs/completion-with-set-u'

Effort to make the command line completion (in contrib/) safe with
"set -u" continues.

* vs/completion-with-set-u:
  completion: avoid aliased command lookup error in nounset mode

contrib/completion/git-completion.bash

@@ -1129,7 +1129,7 @@ __git_pretty_aliases ()
 # __git_aliased_command requires 1 argument
 __git_aliased_command ()
 {
-	local cur=$1 last list word cmdline
+	local cur=$1 last list= word cmdline
 
 	while [[ -n "$cur" ]]; do
 		if [[ "$list" == *" $cur "* ]]; then