Only use phi-search when multiple cursors is enabled

phi-search_mc.el

;; Allow isearch functionality with multiple-cursors
(require 'phi-search)
(setq phi-search-limit 10000)
(add-hook 'multiple-cursors-mode-enabled-hook
          (lambda ()
                 (interactive)
                 (global-set-key (kbd "C-s") 'phi-search)
                 (global-set-key (kbd "C-r") 'phi-search-backward)))
(add-hook 'multiple-cursors-mode-disabled-hook
          (lambda ()
                 (interactive)
                 (global-set-key (kbd "C-s") 'isearch-forward)
                 (global-set-key (kbd "C-r") 'isearch-backward)))