tests: improve hghave error reporting for missing Py OpenSSL

tests/hghave

@@ -202,7 +202,7 b' checks = {'
     "outer-repo": (has_outer_repo, "outer repo"),
     "p4": (has_p4, "Perforce server and client"),
     "pygments": (has_pygments, "Pygments source highlighting library"),
-    "ssl": (has_ssl, "python >= 2.6 ssl module"),
+    "ssl": (has_ssl, "python >= 2.6 ssl module and python OpenSSL"),
     "svn": (has_svn, "subversion client and admin tools"),
     "svn-bindings": (has_svn_bindings, "subversion python bindings"),
     "symlink": (has_symlink, "symbolic links"),