Use PATCH again for patching bots.

This reverts a prior commit, but the earlier commit is fine
functionally; the earlier commit was a temporary measure.

Revert "Use POST, not PATCH, for patching bots."

This reverts commit c3146b23d5d7d134c2b80507eb87033ca375a4db.

(imported from commit ebfcb2bae72c11767f9750412440d40b7a2a4995)

static/js/settings.js

@@ -180,7 +180,7 @@ $(function () {
                 edit_button.hide();
                 $.ajax({
                     url: '/json/bots/' + encodeURIComponent(email),
-                    type: 'POST',
+                    type: 'PATCH',
                     data: formData,
                     cache: false,
                     processData: false,