Four templates use backslash line-continuation on ExecStart
(decnet-bus, decnet-forwarder, decnet-listener, decnet-updater). My
earlier sed inserted StandardOutput= and StandardError= right after
the first ExecStart= line, which split the command and systemd fed
those two lines back to the binary as extra positional arguments —
the bus in particular crashed with:
Got unexpected extra argument
(StandardOutput=append:/var/log/decnet/decnet.bus.log)
Walk the ExecStart block (follow \-continuation lines) and insert
the two Standard* directives AFTER the last continuation line. The
nine single-line ExecStart templates are unaffected in shape but
re-written through the same path to keep the whole set uniform.