Get rid of spurious "threading" entries in trace output.

Lib/trace.py

@@ -493,8 +493,8 @@ class Trace:
         import __main__
         dict = __main__.__dict__
         if not self.donothing:
-            sys.settrace(self.globaltrace)
             threading.settrace(self.globaltrace)
+            sys.settrace(self.globaltrace)
         try:
             exec(cmd, dict, dict)
         finally:
@@ -506,8 +506,8 @@ class Trace:
         if globals is None: globals = {}
         if locals is None: locals = {}
         if not self.donothing:
-            sys.settrace(self.globaltrace)
             threading.settrace(self.globaltrace)
+            sys.settrace(self.globaltrace)
         try:
             exec(cmd, globals, locals)
         finally: