script/update-docs: allow building RC tags

To test docs for release candidates, allow REBUILD_DOC to be a `-rc*`
tag.

Signed-off-by: Toon Claes <[email protected]>

Author: To1ne

script/update-docs.rb

@@ -643,7 +643,7 @@ def local_index_doc(index_fun)
       if gettags
         # find all tags
         tags = `git tag -l --sort=version:refname 'v[12]*'`.strip.split("\n")
-        tags = tags.grep(/v\d([.\d])+$/) # just get release tags
+        tags = tags.grep(/v\d([.\d])+(-rc\d)?$/) # just get release and RC tags
         if tagname
           tags = tags.select { |t| t == tagname }
         end