fix format string in dap-debug-edit-template (#793)

Author: krfantasy

dap-mode.el

@@ -1924,12 +1924,12 @@ the new template can be used normally with `dap-debug'"
     (insert "  (list ")
     (-let ((column (current-column))
            ((fst snd . rst) debug-args))
-      (insert (format "%s %s" fst snd))
+      (insert (format "%s %S" fst snd))
       (cl-loop for (k v) on rst by #'cddr
                do (unless (eq k :program-to-start)
                     (insert "\n")
                     (insert-char ?\s column)
-                    (insert (format "%s %s" k v)))))
+                    (insert (format "%s %S" k v)))))
     (insert "))"))
   (pop-to-buffer "*DAP Templates*")
   (goto-char (point-max)))