gf-complete: update submodule to newest upstream

Keep the tree cleaner!

Signed-off-by: Greg Farnum <gfarnum@redhat.com>

diff --git a/src/erasure-code/jerasure/gf-complete b/src/erasure-code/jerasure/gf-complete
index 70dd94ae38f2d20dd78532a6dfd1310fdfb4a884..39768c55bb00917691364f6f9f7bf688235aedf8 160000 (submodule)
--- a/src/erasure-code/jerasure/gf-complete
+++ b/src/erasure-code/jerasure/gf-complete
@@ -1 +1 @@
-Subproject commit 70dd94ae38f2d20dd78532a6dfd1310fdfb4a884
+Subproject commit 39768c55bb00917691364f6f9f7bf688235aedf8