Another attempt to eradicate ensureDir

See c556a6ea46.

nixos/modules/services/web-servers/apache-httpd/default.nix

@@ -80,7 +80,7 @@ let
 
   # !!! should be in lib
   writeTextInDir = name: text:
-    pkgs.runCommand name {inherit text;} "ensureDir $out; echo -n \"$text\" > $out/$name";
+    pkgs.runCommand name {inherit text;} "mkdir -p $out; echo -n \"$text\" > $out/$name";
 
 
   enableSSL = any (vhost: vhost.enableSSL) allHosts;
@@ -194,7 +194,7 @@ let
     ) null ([ cfg ] ++ subservices);
 
     documentRoot = if maybeDocumentRoot != null then maybeDocumentRoot else
-      pkgs.runCommand "empty" {} "ensureDir $out";
+      pkgs.runCommand "empty" {} "mkdir -p $out";
 
     documentRootConf = ''
       DocumentRoot "${documentRoot}"