(scripted) fix file permission breakage introduced in commit d62bd1

I did this with this command:

git diff d62bd1^..d62bd1 | egrep '^old mode ' -C1 \
    | tr '\n' ' ' | sed 's/diff --git/\n&/g' \
    | sed -r 's|^diff --git a/([^ ]*) b/([^ ]*) old mode 100([0-9]*) new mode 100([0-9]*)|chmod \3 ./\1|' \
    | bash

The first line finds all of the file-permission changes in the commit.

The second line squashes some newlines to get one line per file.  This line
is in the format:
  diff --git a/FILE b/FILE old mode OLDMODE new mode NEWMODE

The third line extracts the values from those lines and transforms the line
into:
  chmod FILE ./OLDMODE

The fourth line (obviously) just executes the output.

1 files changed, 0 insertions, 0 deletions

diff --git a/libre/filesystem/group b/libre/filesystem/group
index 3e6645c83..3e6645c83 100755..100644
--- a/libre/filesystem/group
+++ b/libre/filesystem/group