Fedora: Update required RPMs for Fedora 31

This includes the addition of the python3-virtualenv package required to
provide the virtualenv binary that is no longer present in the image.

Change-Id: Ie8e66d8b9f93063b97f88f41a626daddf235339b
diff --git a/files/rpms/swift b/files/rpms/swift
index eb94d14..745cc2e 100644
--- a/files/rpms/swift
+++ b/files/rpms/swift
@@ -2,7 +2,7 @@
 liberasurecode-devel
 memcached
 pyxattr
-rsync-daemon # dist:f30
+rsync-daemon # dist:f30,f31
 sqlite
 xfsprogs
 xinetd