NERDTree mistakenly overwritten default <C-f> hotkey removed

vim/vimrc

@@ -50,7 +50,6 @@ set updatetime=100
 nnoremap <leader>n :NERDTreeFocus<CR>
 nnoremap <C-n> :NERDTree<CR>
 nnoremap <C-t> :NERDTreeToggle<CR>
-nnoremap <C-f> :NERDTreeFind<CR>
 highlight VertSplit cterm=none
 " Exit Vim if NERDTree is the only window remaining in the only tab.
 autocmd BufEnter * if tabpagenr('$') == 1 && winnr('$') == 1 && exists('b:NERDTree') && b:NERDTree.isTabTree() | quit | endif