nvim: after/plugin/completion: Disable tags completion

We were using tags completion for C projects primarily but now that we
have enabled clangd LSP, disable tags based completion.

nvim/.config/nvim/after/plugin/completion.lua

@@ -30,7 +30,7 @@ require'compe'.setup {
     nvim_lua      = true;
     omni          = false;
     spell         = true;
-    tags          = true;
+    tags          = false;
     treesitter    = true;
     snippets_nvim = false;
     vsnip         = true;