fix(company): company-backends not set in some buffers

Any buffers opened before company-mode was loaded would not have
`company-backends` initialized in them.

Fix: #6261
Fix: #6180
Fix: #5896
Fix: #5672
Fix: #2015

modules/completion/company/config.el

@@ -61,8 +61,7 @@
       :before #'company-begin-backend
       (company-abort)))
 
-  (add-hook 'after-change-major-mode-hook #'+company-init-backends-h 'append)
-
+  (add-hook 'company-mode-hook #'+company-init-backends-h 'append)
 
   ;; NOTE Fix #1335: ensure `company-emulation-alist' is the first item of
   ;;      `emulation-mode-map-alists', thus higher priority than keymaps of