IP prefix tracking was removed in 7d18c40b83.

Index: src/setup.c
==================================================================
--- src/setup.c
+++ src/setup.c
@@ -682,13 +682,10 @@
     @ <p><form action="%R/setup_login_group" method="post"><div>
     login_insert_csrf_secret();
     @ To leave this login group press
     @ <input type="submit" value="Leave Login Group" name="leave">
     @ </form></p>
-    @ <br />For best results, use the same number of <a href="setup_access#ipt">
-    @ IP octets</a> in the login cookie across all repositories in the
-    @ same Login Group.
     @ <hr /><h2>Implementation Details</h2>
     @ <p>The following are fields from the CONFIG table related to login-groups,
     @ provided here for instructional and debugging purposes:</p>
     @ <table border='1' class='sortable' data-column-types='ttt' \
     @ data-init-sort='1'>