Remove default binding for org-table-blank-field

* lisp/org-keys.el: The command isn't useful enough to occupy such a
useful keybinding as "C-c SPC".

lisp/org-keys.el

@@ -174,7 +174,6 @@
 (declare-function org-show-subtree "org" ())
 (declare-function org-sort "org" (&optional with-case))
 (declare-function org-sparse-tree "org" (&optional arg type))
-(declare-function org-table-blank-field "org" ())
 (declare-function org-table-copy-down "org" (n))
 (declare-function org-table-create-or-convert-from-region "org" (arg))
 (declare-function org-table-create-with-table\.el "org-table" ())
@@ -620,7 +619,6 @@ COMMANDS is a list of alternating OLDDEF NEWDEF command names."
 (org-defkey org-mode-map (kbd "RET") #'org-return)
 (org-defkey org-mode-map (kbd "C-j") #'org-return-and-maybe-indent)
 (org-defkey org-mode-map (kbd "C-c ?") #'org-table-field-info)
-(org-defkey org-mode-map (kbd "C-c SPC") #'org-table-blank-field)
 (org-defkey org-mode-map (kbd "C-c +") #'org-table-sum)
 (org-defkey org-mode-map (kbd "C-c =") #'org-table-eval-formula)
 (org-defkey org-mode-map (kbd "C-c '") #'org-edit-special)