Fix spurious line segments inside annotation line ends

AnnotAppearanceBuilder::shortenLineSegmentForEnding was not applied
correctly for some styles. It became visible if no interior color
was set.
6 jobs for bugfix/spurious_lineending in 3 minutes and 49 seconds
Status Job ID Name Coverage
  Build
passed #283594
build

00:03:10

passed #283599
build_android

00:01:26

passed #283595
build_clang_libcpp

00:03:10

passed #283598
build_clazy

00:03:49

passed #283597
build_mingw64_fedora

00:03:41

passed #283596
build_ubuntu_16_04

00:01:48