Remove trailing whitespaces (#1464)

3 jobs for <span class="ref-name">1464</span> in 5 minutes and 37 seconds (queued for 17 seconds)
Status Job ID Name Coverage
  Build
passed #5144
build_bionic

00:02:24

passed #5143
build_stretch

00:02:46

 
  Sign
passed #5145
sign

00:00:26