Revert "Add nvim-lspsignature"

This reverts commit ff9f9dcc162276bc59fdec29f78d244a6aca2cb1.

lua/lsp/init.lua

@@ -48,8 +48,6 @@ local on_attach = function(client, bufnr)
     ]], false)
   end
 
-  require "lsp_signature".on_attach()
-
   local msg = string.format('Language server %s started!' , client.name)
   vim.api.nvim_echo({{msg, 'MoreMsg'}, }, false, {})
 end

lua/plugins.lua

@@ -17,8 +17,6 @@ require('packer').startup(
     -- nvim-lsp configuration
     use 'neovim/nvim-lspconfig'
 
-    use 'ray-x/lsp_signature.nvim'
-
     -- auto-completion engine
     use 'hrsh7th/nvim-compe'