Use has('gui_running') instead of has('gui')

doc/ale.txt

@@ -1806,7 +1806,7 @@ g:ale_pattern_options_enabled                   *g:ale_pattern_options_enabled*
 g:ale_popup_menu_enabled                             *g:ale_popup_menu_enabled*
 
   Type: |Number|
-  Default: `has('gui')`
+  Default: `has('gui_running')`
 
   When this option is set to `1`, ALE will show code actions and rename
   capabilities in the right click mouse menu when there's a LSP server or