vim: Move CycleSpellLang into keys.vim

See ba3a54fc4 ("vim: Move numbertoggle autocmd into settings.vim").

.config/vim/vimrc.d/40-keys.vim

@@ -46,6 +46,14 @@ noremap <leader>[s [s1z=<C-O>
 noremap <leader>]S ]S1z=<C-O>
 noremap <leader>[S [S1z=<C-O>
 
+" Toggle spell language between German and English
+function! CycleSpellLang()
+	if (&spelllang == 'en')
+		set spelllang=de
+	else
+		set spelllang=en
+	endif
+endfunction
 " Toggle spell, cycle and set spelllang
 map <leader>st :set spell=!&spell<CR>
 map <leader>sc :call CycleSpellLang()<CR>

.config/vim/vimrc.d/70-functions.vim

@@ -1,12 +1,4 @@
 " Functions """"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
-" Toggle spell language between German and English
-function! CycleSpellLang()
-	if (&spelllang == 'en')
-		set spelllang=de
-	else
-		set spelllang=en
-	endif
-endfunction
 
 " Check time every second to read file changes.
 if (exists('+autoread') && &autoread)