tracing/pyruntraced: pymain changed signature to accept prog in argv[0]

See nexedi/pygolang@21756bd3.

tracing/cmd/pyruntraced

 #!/usr/bin/env python
 # -*- coding: utf-8 -*-
-# Copyright (C) 2018-2019  Nexedi SA and Contributors.
+# Copyright (C) 2018-2020  Nexedi SA and Contributors.
 #                          Kirill Smelkov <kirr@nexedi.com>
 #
 # This program is free software: you can Use, Study, Modify and Redistribute
@@ -249,6 +249,7 @@ def die(msg):
 # main mimics `python ...`,
 # but with tracepoints already attached.
 def main():
+    prog = sys.argv[0]
     argv = sys.argv[1:]
     if not argv:
         usage(sys.stderr)
@@ -290,7 +291,7 @@ def main():
         execfile(t, globals())
 
     # now mimic `python ...`
-    pymain(argv)
+    pymain([prog] + argv)
 
 
 if __name__ == '__main__':