Remove `org-enable-fixed-width-editor'

* lisp/org.el (org-enable-fixed-width-editor): Remove variable.

etc/ORG-NEWS

@@ -334,7 +334,7 @@ dynamic block in ~org-dynamic-block-alist~.
 *** ~org-table-cell-left~
 *** ~org-table-cell-right~
 *** ~org-habit-toggle-display-in-agenda~
-** Removed functions
+** Removed functions and variables
 *** Removed Org Drill
 
 You can install it back from MELPA.
@@ -346,6 +346,8 @@ You can install it back from MELPA.
 It has been deprecated in favour of ~org-attach-id-dir~ which is less
 ambigous given the restructured org-attach.
 
+*** ~org-enable-fixed-width-editor~
+This variable was not used throught the code base.
 ** Miscellaneous
 *** Change signature for ~org-list-to-subtree~
 The function now accepts the level of the subtree as an optional

lisp/org.el

@@ -1698,13 +1698,6 @@ make an intelligent decision whether to insert a blank line or not."
   :group 'org-edit-structure
   :type 'hook)
 
-(defcustom org-enable-fixed-width-editor t
-  "Non-nil means lines starting with \":\" are treated as fixed-width.
-This currently only means they are never auto-wrapped.
-When nil, such lines will be treated like ordinary lines."
-  :group 'org-edit-structure
-  :type 'boolean)
-
 (defgroup org-sparse-trees nil
   "Options concerning sparse trees in Org mode."
   :tag "Org Sparse Trees"