Fixes #528 bundled dependency builds on some Linux

netj · netj · commit 6722361d1358 · 2016-03-28T18:50:56.000-07:00
namely Arch Linux which puts linux-vdso.
diff --git a/extern/buildkit b/extern/buildkit
@@ -1 +1 @@
-Subproject commit 4aeb259ccb2b435cb45aca7f64e60cf4f5196f6a
+Subproject commit 8138f3e89756abe7f0de80a8ecfab6c466eb15bc
