hunks: remove test for empty branch for changes plugin

Because changes plugin does not rely on git
Also remove the test of the local variable for the changes plugin
whether it is enabled or not, this is taken care of in the changes
plugin

autoload/airline/extensions/hunks.vim

@@ -50,9 +50,6 @@ function! s:get_hunks_gitgutter() abort
 endfunction
 
 function! s:get_hunks_changes() abort
-  if !get(b:, 'changes_view_enabled', 0) || s:is_branch_empty()
-    return []
-  endif
   let hunks = changes#GetStats()
   return hunks == [0, 0, 0] ? [] : hunks
 endfunction