The packages in the official Debian repos have slightly more
up-to-date metadata. This change adjusts our metadata.
This includes the change from Debian repo to let debhelper (>= 10.3)
handle the meson build of keyman-keyboardprocessor.
If (re-)starting ibus fails for whatever reason we should simply
ignore the failure instead of failing the entire installation/
uninstallation.
This fixes#3902.
If for whatever reason ibus wasn't running for the current user
the installation failed previously, leaving the user in a broken
state until he reboots and tries the installation again. This change
detects this situation and skips restarting ibus.
