Inherit foreground color from region face in evil-search-highlight-persist

Fits better material theme, I did not test other themes with it but
we can assume that the background and foreground combination for
region face is correct in most of the themes.

spacemacs/packages.el

@@ -976,7 +976,8 @@ Example: (evil-map visual \"<\" \"<gv\")"
       (defun spacemacs/adaptive-evil-highlight-persist-face ()
         (set-face-attribute 'evil-search-highlight-persist-highlight-face nil
                             :inherit 'region
-                            :background nil))
+                            :background nil
+                            :foreground nil))
       (spacemacs/adaptive-evil-highlight-persist-face))))
 
 (defun spacemacs/init-evil-surround ()