* hydra: do not show build history if there are no previous builds

Dependencies

• [2] 2R7GHSA4 * hydra: added initial version of build graph
• [3] TCXFZZFN * hydra: make chart zoomable and clickable
• [4] WHAFVCEI
• [5] ZI535LI6 * hydra: 'new' UI for project/jobset/job/build
• [6] VCOSLZRP
• [7] J5UVLXOK * Start of a basic Catalyst web interface.

Change contents

• replacement in src/root/build.tt at line 92
  [2.788]→[2.788:841](∅→∅)
  − <li><a href="#tabs-history">History chart</a></li>
  [2.788]

  [3.4253]
  + [% IF prevBuilds %]<li><a href="#tabs-history">History chart</a></li>[% END %]
• replacement in src/root/build.tt at line 437
  [3.763]→[2.844:845](∅→∅)
  −
  [3.763]

  [2.845]
  + [% IF prevBuilds %]
• edit in src/root/build.tt at line 516
  [2.2840]

  [2.2840]
  + [% END %]