hydra: removed need for HYDRA_BUILD_BASEURL env variable

Dependencies

• [2] CXRCPDSQ * added support for twitter notification
• [3] 3BKF6P72 * Use Nix's negative caching.
• [4] OG7BEM57
• [*] 7YBYT2LQ

Change contents

• replacement in src/script/hydra_build.pl.in at line 34
  [2.193]→[2.193:247](∅→∅)
  − my $addURL = defined $ENV{'HYDRA_BUILD_BASEURL'};
  [2.193]

  [2.247]
  + my $addURL = defined $config{'base_uri'};
• replacement in src/script/hydra_build.pl.in at line 40
  [2.559]→[2.559:618](∅→∅)
  − my $url = $ENV{'HYDRA_BUILD_BASEURL'}."/".$build->id ;
  [2.559]

  [3.400]
  + my $url = $config{'base_uri'}."/build/".$build->id ;