bash: don't offer remote transport helpers as subcommands

Since commits a2d725b (Use an external program to implement fetching
with curl, 2009-08-05) and c9e388b (Make the
"traditionally-supported" URLs a special case, 2009-09-03) remote
transport helpers like 'remote-ftp' and 'remote-curl' are offered by the
completion script as available subcommands.  Not good, since they are
helpers, therefore should not be offered, so filter them out.

Signed-off-by: SZEDER Gábor <szeder@ira.uka.de>
Acked-by: Shawn O. Pearce <spearce@spearce.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

contrib/completion/git-completion.bash

@@ -571,6 +571,7 @@ __git_list_porcelain_commands ()
 		read-tree)        : plumbing;;
 		receive-pack)     : plumbing;;
 		reflog)           : plumbing;;
+		remote-*)         : transport;;
 		repo-config)      : deprecated;;
 		rerere)           : plumbing;;
 		rev-list)         : plumbing;;