[lldb-dap[test] Don't pass --listen to debugserver

Fixes "debugserver: unrecognized option `--listen'"
diff --git a/lldb/test/API/tools/lldb-dap/attach/TestDAP_attachByPortNum.py b/lldb/test/API/tools/lldb-dap/attach/TestDAP_attachByPortNum.py
index 18786fc..51f62b7 100644
--- a/lldb/test/API/tools/lldb-dap/attach/TestDAP_attachByPortNum.py
+++ b/lldb/test/API/tools/lldb-dap/attach/TestDAP_attachByPortNum.py
@@ -41,8 +41,6 @@
         args = []
         if lldbplatformutil.getPlatform() == "linux":
             args = ["gdbserver"]
-        elif lldbplatformutil.getPlatform() == "macosx":
-            args = ["--listen"]
         if lldb.remote_platform:
             args += ["*:0"]
         else: