Channel rename: do not leave the old name behind

Dependencies

• [2] SXEYMYF7 Fixing the bad changes in history (unfortunately, by rebooting).

Change contents

• edit in libpijul/src/pristine/sanakirja.rs at line 1040
  [2.566888]

  [2.566888]
  + self.txn.del(

  + &mut self.rng,

  + &mut self.channels,

  + UnsafeSmallStr::from_small_str(channel.borrow().name.as_small_str()),

  + None,

  + )?;