oas3.1 initial support - fix oas3.1 code branch

Author: frantuma

modules/swagger-parser-v3/src/main/java/io/swagger/v3/parser/util/OpenAPIDeserializer.java

@@ -1783,9 +1783,11 @@ public Parameter getParameter(ObjectNode obj, String location, ParseResult resul
 				} else {
 					parameter.set$ref(ref.textValue());
 				}
-				String desc = getString("description", obj, false, location, result);
-				if (StringUtils.isNotBlank(desc)) {
-					parameter.setDescription(desc);
+				if (result.isOpenapi31()) {
+					String desc = getString("description", obj, false, location, result);
+					if (StringUtils.isNotBlank(desc)) {
+						parameter.setDescription(desc);
+					}
 				}
 				return parameter;
 			} else {
@@ -3587,7 +3589,6 @@ public Schema getJsonSchema(ObjectNode node, String location, ParseResult result
 				}
 			} else {
 				result.invalidType(location, "$ref", "string", node);
-				return null;
 			}
 		}