enhance: respect laststatus from user

Users laststatus option is kept as is unless globalstatus option is set.

closes #670

lua/lualine.lua

@@ -269,12 +269,16 @@ local function set_statusline()
   if next(config.sections) ~= nil or next(config.inactive_sections) ~= nil then
     vim.cmd('autocmd lualine VimResized * redrawstatus')
     vim.go.statusline = "%{%v:lua.require'lualine'.statusline()%}"
-    vim.go.laststatus = config.options.globalstatus and 3 or 2
+    if config.options.globalstatus then
+      vim.go.laststatus = 3
+    end
   elseif vim.go.statusline == "%{%v:lua.require'lualine'.statusline()%}" then
     vim.go.statusline = ''
+    if config.options.globalstatus then
       vim.go.laststatus = 2
     end
   end
+end
 
 -- lualine.statusline function
 --- Draw correct statusline for current window