fix formatting of \ continued shell examples in man pages

doc/git-annex-filter-branch.mdwn and one other file have these, and no
other files have \ at the end of line, so this should be safe

diff --git a/Build/mdwn2man b/Build/mdwn2man
index 38c0f4ba9240fc1ea6d034987d67dec1b9b76047..1eb0246a7dc3705fe147b6cd57e67d424a5992e9 100755 (executable)
--- a/Build/mdwn2man
+++ b/Build/mdwn2man
@@ -22,6 +22,7 @@ while (<>) {
        s/^Warning:.*mdwn2man.*//g;
        s/^$/.PP\n/;
        s/^\*\s+(.*)/.IP "$1"/;
+       s/\\$/\\\\/;
        next if $_ eq ".PP\n" && $skippara;
        if (/^.IP /) {
                $inlist=1;