neovim: un-deprecate the configure option

The `programs.neovim.configure` option is consistent with NixOS's
`wrapNeovim` and offers features not supported by the `extraConfig`
and `plugins` option pair.

Closes nix-community#971

modules/programs/neovim.nix

@@ -148,8 +148,8 @@ in
 
           </para><para>
 
-          This option is deprecated. Please use the options <varname>extraConfig</varname>
-          and <varname>plugins</varname> which are mutually exclusive with this option.
+          This option is mutually exclusive with <varname>extraConfig</varname>
+          and <varname>plugins</varname>.
         '';
       };
 
@@ -193,11 +193,6 @@ in
       }
     ];
 
-    warnings = optional (cfg.configure != {}) ''
-      The programs.neovim.configure option is deprecated. Please use
-      extraConfig and package option.
-    '';
-
     home.packages = [ cfg.finalPackage ];
 
     programs.neovim.finalPackage = pkgs.wrapNeovim cfg.package {