Do not use ivy for completion in regions

This makes eshell completion use drop down menues instead of the standard
complete-until-ambiguous style I am used to.  Moreover, in Org Babel shell
source blocks, ivy completion in region causes a drop down menu of possible
commands to appear after a block has been created and entered for the first
time, which not only is annoying, but also sometimes causes to cursor to
disappear (set `cursor-type' to 'bar to revert).

init.el

@@ -2142,7 +2142,8 @@
                                          (counsel-describe-variable . "^")
                                          (man . "^")
                                          (woman . "^"))
-              ivy-use-selectable-prompt t)
+              ivy-use-selectable-prompt t
+              ivy-do-completion-in-region nil)
   :config (add-to-list 'ivy-completing-read-handlers-alist
                        '(org-capture . completing-read-default)))