[neon-notifications] umbrello new version 18.08.3

[Neon CI]

https://build.neon.kde.org/job/watcher_release_kde_umbrello/218/display/redirect

#<Debian::UScan::DEHS::Package:0x0000562549e72a88 @name="umbrello", @debian_uversion="18.08.2", @debian_mangled_uversion="18.08.2", @upstream_version="18.08.3", @upstream_url="http://download.kde.internal.neon.kde.org/stable/applications/18.08.3/src/umbrello-18.08.3.tar.xz", @status="Newer version available">