ssl 0.7: tests require ocaml 4.08

Author: mseri

packages/ssl/ssl.0.7.0/opam

@@ -9,7 +9,6 @@ bug-reports: "https://github.com/savonet/ocaml-ssl/issues"
 depends: [
   "dune" {>= "2.7"}
   "ocaml" {>= "4.03.0"}
-  "ocaml" {with_test & >= "4.08.0"}
   "dune-configurator"
   "conf-libssl"
   "alcotest" {with-test}
@@ -26,7 +25,7 @@ build: [
     "-j"
     jobs
     "@install"
-    "@runtest" {with-test}
+    "@runtest" {with-test & ocaml:version >= "4.08.0"}}
     "@doc" {with-doc}
   ]
 ]