Add a warning for code like:
  assert (0, 'message')

An empty tuple does not create a warning.  While questionable usage:
  assert (), 'message'

should not display a warning.  Tested manually.
The warning message could be improved.  Feel free to update it.
diff --git a/Misc/NEWS b/Misc/NEWS
index e778b87..ccb7baa 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -12,6 +12,8 @@
 Core and builtins
 -----------------
 
+- Add a warning when asserting a non-empty tuple which is always true.
+
 - Issue #2179: speed up with statement execution by storing the exit method
   on the stack instead of in a temporary variable (patch by Jeffrey Yaskin)