Setting blog options to false breaks a generated site

[sarahmonster]

If you set enableBlogAuthors or enableBlogTags to false in your SiteConfig, Gatsby freaks out:

 ERROR #11321  PLUGIN

"gatsby-node.js" threw an error while running the createPages lifecycle:

Field "authors" must not have a selection since type "[String]" has no subfields.

GraphQL request:11:23
10 |             fields {
11 |               authors {
   |                       ^
12 |                 id,Field "tags" must not have a selection since type "[String]" has no subfields.

GraphQL request:21:20
20 |               title
21 |               tags {
   |                    ^
22 |                 id

failed createPages - 0.072s
success createPagesStatefully - 0.035s
success onPreExtractQueries - 0.003s
success update schema - 0.022s

 ERROR #85909  GRAPHQL

Field "tags" must not have a selection since type "[String]" has no subfields

File: src/templates/Blog/index.js:87:18

Looks like the queries may need to be adjusted to account for these settings.

As a sidenote, I'm okay with not allowing people to remove tags and authors from the blog, since this is probably rare—most people who want a blog would be likely to want certainly tags, but possibly authors as well. And having authors in a set file, even if there's only a single author, makes it more straightforward to show an author bio box or similar.

See also #25.