Fix completion of remote scp filenames with spaces.

Backslash escaping adds 3 backslashes, of which we want to remove 2,
not 4 when unescaping.

CHANGES

@@ -24,7 +24,7 @@ bash-completion (2.x)
   * Apply pine completion to alpine too.
   * Remove many unnecessary short option completions where long ones exist.
   * Improve configure, cvs, gkrellm, lftp, mdadm, modprobe, mplayer,
-    mysqladmin, service, ssh, and general hostname completions.
+    mysqladmin, service, scp, ssh, and general hostname completions.
   * Add abook and wtf completion, based on work by Raphaël Droz.
   * Add k3b and lftpget completion.
   * Don't overwrite other host completions when completing from multiple

contrib/ssh

@@ -177,7 +177,7 @@ _scp()
         userhost=${cur%%?(\\):*}
         path=${cur#*:}
         # unescape spaces
-        path=${path//\\\\\\\\ / }
+        path=${path//\\\\ / }
         if [ -z "$path" ]; then
             # default to home dir of specified user on remote host
             path=$(ssh -o 'Batchmode yes' $userhost pwd 2>/dev/null)