Fix mdbook redirection table (#1567)

There must have been a merge conflict at some point which resulted in a
malformed table. The result was that most redirects were blindly ignored
by `mdbook`.

I noticed it for
https://google.github.io/comprehensive-rust/enums.html which stopped
working because of this.

I took out the memory management redirect since we already have a file
where redirect would be (`mdbook` helpfully emits an error in this
case).

.github/workflows/build.yml

@@ -136,7 +136,13 @@ jobs:
           MDBOOK_OUTPUT='{"xgettext": {"pot-file": "messages.pot"}}' mdbook build -d po
           msgfmt -o /dev/null --statistics po/messages.pot
 
+      # Build the translation without redirects just like publish.yml does.
+      - name: Build ${{ matrix.language }} translation
+        if: matrix.language != 'en'
+        run: MDBOOK_OUTPUT__HTML__REDIRECT='{}' mdbook build
+
       - name: Build course
+        if: matrix.language == 'en'
         run: mdbook build
 
       - name: Zip exercise templates