tools.reader.edn throws on reading "(+)" from java.io.PushbackReader

Repro:

This error happens when you have more than one unread in a row.

A trace of what happens when running the repro. First add some logging in reader_types:

Then run the repro:

Proposed solution
The patch prevents two successive unreads by only unreading when necessary: at the end of the token.

The trace with the patch applied: