Clean up ks_meta_data construction

Simplify ks_meta_data construction in few places by using the default
arguments.

Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>

tests/urchin/cql_test_env.cc

@@ -98,9 +98,7 @@ public:
             ks_meta_data ksm(ks_name,
                     "org.apache.cassandra.locator.SimpleStrategy",
                     std::unordered_map<sstring, sstring>(),
-                    false,
-                    std::vector<schema_ptr>(),
-                    shared_ptr<user_types_metadata>()
+                    false
                     );
             ks.create_replication_strategy(ksm);
         });

thrift/handler.cc

@@ -467,8 +467,7 @@ public:
                         to_sstring(ks_def.strategy_class),
                         std::unordered_map<sstring, sstring>(),//ks_def.strategy_options,
                         ks_def.durable_writes,
-                        cf_defs,
-                        shared_ptr<user_types_metadata>());
+                        cf_defs);
                 auto& ks = db.find_keyspace(ks_def.name);
                 ks.create_replication_strategy(ksm);
             });