spacemacs-editing-visual: fix term-cursor logic

As reported in comment of PR syl20bnr#15680, it should be enabled in non graphical usage.

Author: lebensterben

layers/+spacemacs/spacemacs-editing-visual/packages.el

@@ -159,7 +159,7 @@
   (use-package term-cursor
     :defer t
     :init
-    (when (display-graphic-p)
+    (unless (display-graphic-p)
      (global-term-cursor-mode))))
 
 (defun spacemacs-editing-visual/init-volatile-highlights ()