reftest: update pin test

tests/reftests/pin.test

@@ -98,9 +98,16 @@ The following actions will be performed:
   - install bar dev (pinned)
 ===== 2 to install =====
 
-<><> Processing actions <><><><><><><><><><><><><><><><><><><><><><><><><><><><>
--> retrieved bar.dev  (file://${BASEDIR}/bar)
--> retrieved qux.dev  (file://${BASEDIR}/qux)
--> installed qux.dev
--> installed bar.dev
-Done.
+The following system packages will first need to be installed:
+    another-inexistant inexistant
+
+<><> Handling external dependencies <><><><><><><><><><><><><><><><><><><><><><>
+Let opam run your package manager to install the required system packages?
+(answer 'n' for other options) [Y/n] n
+[NOTE] Use 'opam option depext-run-installs=false' if you don't want to be prompted again.
+This command should get the requirements installed:
+
+    apt-get install another-inexistant inexistant
+
+You can retry with '--assume-depexts' to skip this check, or run 'opam option depext=false' to permanently disable handling of system packages altogether.
+# Return code 10 #