Fixes linking problem with libressl

uniform-io.cabal

@@ -111,7 +111,7 @@ library
   includes: ds.h
   install-includes: ds.h
   C-Sources: src/System/IO/Uniform/ds.c
-  extra-libraries: ssl, pthread
+  extra-libraries: ssl, crypto, pthread
 
 Test-suite targets
   type: detailed-0.9