Update libssh2 to 1.9.0

tiennou · tiennou · commit 590054004429 · 2021-05-07T23:38:56.000+02:00
diff --git a/External/libssh2 b/External/libssh2
@@ -1 +1 @@
-Subproject commit f15b1e297f72882214988101ccdc5e6ad30d7e6e
+Subproject commit 42d37aa63129a1b2644bf6495198923534322d64
