fix(suggestion): Trigger suggestion on InsertEnter (zbirenbaum#318)

Author: jsongerber

lua/copilot/suggestion.lua

@@ -324,7 +324,7 @@ local function trigger(bufnr, timer)
   local _timer = copilot._copilot_timer
   copilot._copilot_timer = nil
 
-  if bufnr ~= vim.api.nvim_get_current_buf() or timer ~= _timer or vim.fn.mode() ~= "i" then
+  if bufnr ~= vim.api.nvim_get_current_buf() or (_timer ~= nil and timer ~= _timer) or vim.fn.mode() ~= "i" then
     return
   end