fix nrbuilds query

Dependencies

• [2] BKOIYITR added some json responses
• [3] SHYRGAWZ hydra: when no external url is given for diff's of git/hg input, revert to a diff done on a local available clone

Change contents

• replacement in src/lib/Hydra/Controller/API.pm at line 192
  [2.5676]→[2.5676:5885](∅→∅)
  − my @stats = $c->model('DB::Builds')->search($filter, {select => ["count(*)"], as => ["nr"], group_by => ["timestamp - timestamp % $base"], order_by => "timestamp - timestamp % $base DESC", rows => $nr}) ;
  [2.5676]

  [2.5885]
  + my @stats = $c->model('DB::Builds')->search($filter, {select => [{ count => "*" }], as => ["nr"], group_by => ["timestamp - timestamp % $base"], order_by => "timestamp - timestamp % $base DESC", rows => $nr}) ;