Updates downloaders: 57c69a7 Tails now is amd64 only

diff --git a/downloaders b/downloaders
index f7bb3d39f3b79f5f7cbd4e8facb655da616479b8..57c69a703cf24beb10a82160f68e3b2d8f975c3a 160000 (submodule)
--- a/downloaders
+++ b/downloaders
@@ -1 +1 @@
-Subproject commit f7bb3d39f3b79f5f7cbd4e8facb655da616479b8
+Subproject commit 57c69a703cf24beb10a82160f68e3b2d8f975c3a