Add note about backwards compatibility.

taus-semmle · taus-semmle · commit e22707895376 · 2019-04-08T17:55:48.000+02:00
diff --git a/python/config/suites/lgtm/python2-lgtm b/python/config/suites/lgtm/python2-lgtm
@@ -1 +1,4 @@
+# This file (and the other python2- files in this directory) is present for
+# backwards compatibility, and can be removed once we reach version 1.23.
+
 @import "python-lgtm"
