remove lsp_signature from on_attach

lua/navigator/lspclient/attach.lua

@@ -21,10 +21,7 @@ M.on_attach = function(client, bufnr)
   end
   log("attaching", bufnr, client.name, uri)
   trace(client)
-  local hassig, sig = pcall(require, "lsp_signature")
-  if hassig then
-    sig.on_attach()
-  end
+
   diagnostic_map(bufnr)
   -- add highlight for Lspxxx
   require"navigator.lspclient.highlight".add_highlight()

lua/navigator/lspclient/mapping.lua

@@ -194,6 +194,7 @@ function M.setup(user_opts)
   vim.lsp.handlers["textDocument/publishDiagnostics"] =
       require"navigator.diagnostics".diagnostic_handler
 
+  -- TODO: when active signature merge to neovim, remove this setup:
   local hassig, sig = pcall(require, "lsp_signature")
   if not hassig then
     vim.lsp.handlers["textDocument/signatureHelp"] = require"navigator.signature".signature_handler