fix: check if locustio installed

httprunner/plugins/locusts/cli.py

@@ -2,6 +2,7 @@ try:
     # monkey patch ssl at beginning to avoid RecursionError when running locust.
     from gevent import monkey
     monkey.patch_ssl()
+    from locust import main as locust_main
 except ImportError:
     msg = """
 Locust is not installed, install first and try again.
@@ -61,8 +62,7 @@ def gen_locustfile(testcase_file_path):
 
 
 def start_locust_main():
-    from locust.main import main
-    main()
+    locust_main.main()
 
 
 def start_master(sys_argv):