[#1968] Add org.jooq.Meta returned from Executor.meta() to return a

wrapped JDBC DatabaseMetaData object - Fixed issue with databases that
do not have any schema

jOOQ/src/main/java/org/jooq/impl/MetaImpl.java

@@ -149,6 +149,11 @@ class MetaImpl implements Meta {
                     result.add(new MetaSchema(name));
                 }
 
+                // There should always be at least one (empty) schema in a database
+                if (result.isEmpty()) {
+                    result.add(new MetaSchema(""));
+                }
+
                 return result;
             }
             catch (SQLException e) {