Update libtasn1 to 4.19.0.

Signed-off-by: Simon Josefsson <simon@josefsson.org>

diff --git a/devel/libtasn1 b/devel/libtasn1
index 6e8c03bc4a42f9783a91a8166e4443ba59ba5a97..2b7ee166f031bea63c5e7badcedc69f1cea69c89 160000 (submodule)
--- a/devel/libtasn1
+++ b/devel/libtasn1
@@ -1 +1 @@
-Subproject commit 6e8c03bc4a42f9783a91a8166e4443ba59ba5a97
+Subproject commit 2b7ee166f031bea63c5e7badcedc69f1cea69c89