Don't do completion in command mode

This is stopping normal expansion of things like `%:h` for the directory
of the current buffer.

after/plugin/completion.lua

@@ -74,15 +74,6 @@ cmp.setup.cmdline({ "/", "?" }, {
   },
 })
 
-cmp.setup.cmdline(":", {
-  mapping = cmp.mapping.preset.cmdline(),
-  sources = cmp.config.sources({
-    { name = "path" },
-  }, {
-    { name = "cmdline" },
-  }),
-})
-
 vim.cmd [[
   augroup DadbodSql
     au!