Update Git repository name

wiki/src/contribute/working_together/roles/sysadmins.mdwn

@@ -198,7 +198,7 @@ Below, importance level is evaluated based on:
 * access: Tails core developers only
 * tools: [[!debpts bitcoind]]
 * configuration: `bitcoind` class in [[!tails_gitweb_repo puppet-bitcoind]]
-* Vcs-Git: [[!tails_gitweb_repo bitcoin]] and [[!tails_gitweb_repo bitcoin_libunivalue]]
+* Vcs-Git: [[!tails_gitweb_repo bitcoin]] and [[!tails_gitweb_repo libunivalue]]
 * importance: medium
 * To save disk space: as the `bitcoin@bitcoin.lizard` user, run
   `bitcoin-cli getblockcount` to get the ID of the last block,