Update submodules: installer (new commits)

installer:
    d6d9123 Shane Mc Cormack <shane@dmdirc.com>
            Fix LICENCE file name and add AUTHORS file.

            Gerrit: http://gerrit.dmdirc.com/2648

Change-Id: I0e1d67b708ca146fd58f145c657abde981473fda

modules/installer

@@ -1 +1 @@
-Subproject commit d104806818e8719b763c0ab6f5d4b96155f4759e
+Subproject commit d6d9123663774ec3273238a0e8e2316efcb2f3c5