tests: update ssl requirement for test-https.t

hgweb requires OpenSSL for serving https.

tests/hghave

@@ -173,6 +173,8 b' def has_outer_repo():'
 def has_ssl():
     try:
         import ssl
+        import OpenSSL
+        OpenSSL.SSL.Context
         return True
     except ImportError:
         return False