service: keep a pending reload across a second conf reload

A service whose condition goes into flux during a reload is paused
with its reload still pending.  If another reload was requested in
the meantime, re-parsing its unchanged .conf file cleared the pending
mark, so the service was resumed without ever being reloaded.  Seen
with sshd <pid/syslogd> on Infix, where a configuration change that
touched both landed as two reloads in a row and sshd kept its old
listen addresses.

The mark is only ever cleared once the change has been applied, so a
mark that is still set when the file is parsed again means exactly
that: not applied yet.  Leave it alone.

Signed-off-by: Joachim Wiberg <troglobit@gmail.com>

test/Makefile.am

@@ -33,6 +33,7 @@ EXTRA_DIST		+= bootstrap-crash.sh
 EXTRA_DIST		+= script-timeout.sh
 EXTRA_DIST		+= crashing.sh
 EXTRA_DIST		+= dep-chain-reload.sh
+EXTRA_DIST		+= reload-while-paused.sh
 EXTRA_DIST		+= depserv.sh
 EXTRA_DIST		+= devmon.sh
 EXTRA_DIST		+= failing-sysv.sh
@@ -78,6 +79,7 @@ TESTS			+= cond-start-task.sh
 TESTS			+= script-timeout.sh
 TESTS			+= crashing.sh
 TESTS			+= dep-chain-reload.sh
+TESTS			+= reload-while-paused.sh
 TESTS			+= depserv.sh
 TESTS			+= devmon.sh
 TESTS			+= failing-sysv.sh