Restart HTTP built-in on every SIGHUP

Now the HTTP built-in will be restart every time Monitorix received the
SIGHUP signal. This should also fix thos annoying sporadic hangups of the
HTTP server, and also a truncation in the recent rotated logfile.

Changes

@@ -17,6 +17,9 @@
   setup the owner, group and permission bits to that directory every time
   Monitorix is started.
   	(thanks to Sander Bos for pointing this out)
+- Added to restart the HTTP built-in every time Monitorix receives the SIGHUP
+  signal. This should also fix sporadic hangups in the HTTP and a truncation in
+  the rotated logfile.
 - Fixed a bad memory scaling in *BSD systems.
 - Fixed in 'process.pm' to fully honour the option 'netstats_in_bps'.
 - Fixed to force Monitorix to be started at the end of boot in systemd-based

monitorix

@@ -72,6 +72,8 @@ sub HUP_handler {
 	my ($signal) = @_;
 	my $myself = (caller(0))[3];
 
+	return if $options{n};	# only continue if it's a daemon
+
 	my (undef, undef, $uid) = getpwnam($config{httpd_builtin}->{user});
 	my (undef, undef, $gid) = getgrnam($config{httpd_builtin}->{group});
 
@@ -85,11 +87,16 @@ sub HUP_handler {
 	chmod(0600, $config{log_file});
 	logger("$myself: opening a new log file.");
 
-	# create the HTTPd logfile
-	open(OUT, "> " . $config{httpd_builtin}->{log_file});
-	close(OUT);
-	chown($uid, $gid, $config{httpd_builtin}->{log_file});
-	chmod(0600, $config{httpd_builtin}->{log_file});
+	# restart HTTP built-in
+	if(lc($config{httpd_builtin}->{enabled}) eq "y") {
+		if(defined($config{httpd_pid})) {
+			require HTTPServer;
+			kill(15, $config{httpd_pid});
+			kill(9, $config{httpd_pid});
+			httpd_setup(\%config, $options{d});
+			logger("Restarted built-in HTTP server (pid $config{httpd_pid}).") if (defined($config{httpd_pid}));
+		}
+	}
 }
 
 sub daemonize {