fix(接口测试): 修复场景导入非标准JMX文件失败问题

--bug=1027337 --user=王孝刚 【接口测试】接口自动化中导入jmeter文件失败
https://www.tapd.cn/55049933/s/1386032

api-test/backend/src/main/java/io/metersphere/api/parse/scenario/JMeterParser.java

@@ -106,7 +106,7 @@ public class JMeterParser extends ApiImportAbstractParser<ScenarioImport> {
 
             MsScenario scenario = new MsScenario();
             scenario.setReferenced("IMPORT");
-
+            if (testPlan.getArray()[0] instanceof TestPlan) {
                 TestPlan plan = (TestPlan) testPlan.getArray()[0];
                 if (plan.getArguments() != null) {
                     List<ScenarioVariable> variables = new LinkedList<>();
@@ -127,6 +127,9 @@ public class JMeterParser extends ApiImportAbstractParser<ScenarioImport> {
                     scenario.setHashTree(new LinkedList<>());
                 }
                 formatHashTree(testPlan.getTree(plan), scenario);
+            } else {
+                formatHashTree(testPlan, scenario);
+            }
             this.projectId = request.getProjectId();
             ScenarioImport scenarioImport = new ScenarioImport();
             scenarioImport.setData(parseObj(scenario, request));