sepolicy/manpage.py: make output deterministic

The list entries in the alphabetically grouped dict are
not sorted, which results in non-deterministic output for
index.html.

Sort entries of those lists to make the output deterministic
to be able to have reproducible builds.

See https://reproducible-builds.org/ for reasoning.
This patch was done while working on reproducible builds for openSUSE.

Signed-off-by: Cathy Hu <cahu@suse.de>
Acked-by: Petr Lautrbach <lautrbach@redhat.com>

python/sepolicy/sepolicy/manpage.py

@@ -156,7 +156,7 @@ def get_alphabet_manpages(manpage_list):
             if j.split("/")[-1][0] == i:
                 temp.append(j.split("/")[-1])
 
-        alphabet_manpages[i] = temp
+        alphabet_manpages[i] = sorted(temp)
 
     return alphabet_manpages