Merge branch 'lazy_umount' into 'master'

added -l to umount commands

the log folder is not deleted, because the **umount** command needs to be lazy, that's why we added the **-l** argument.

```
Tue Mar 21 23:59:01 UTC 2017 umount: /home/0/57/log: target is busy
Tue Mar 21 23:59:01 UTC 2017 (In some cases useful info about processes that
Tue Mar 21 23:59:01 UTC 2017 use the device is found by lsof(8) or fuser(1).)
Tue Mar 21 23:59:01 UTC 2017 rm: cannot remove '/home/0/57/log': Device or resource busy
```

See merge request !561

Author: Till Brehm

server/plugins-available/apache2_plugin.inc.php

@@ -643,7 +643,7 @@ function update($event_name, $data) {
 
 				//* Unmount the old log directory bfore we move the log dir
 				//exec('fuser -km '.escapeshellcmd($old_dir.'/log'));
-				exec('umount '.escapeshellcmd($data['old']['document_root'].'/log'));
+				exec('umount -l '.escapeshellcmd($data['old']['document_root'].'/log'));
 
 				//* Create new base directory, if it does not exist yet
 				if(!is_dir($new_dir)) $app->system->mkdirpath($new_dir);
@@ -726,7 +726,7 @@ function update($event_name, $data) {
 
 			//* Unmount log directory
 			//exec('fuser -km '.escapeshellarg($data['old']['document_root'].'/'.$old_log_folder));
-			exec('umount '.escapeshellarg($data['old']['document_root'].'/'.$old_log_folder));
+			exec('umount -l '.escapeshellarg($data['old']['document_root'].'/'.$old_log_folder));
 		}
 
 		//* Create the log dir if nescessary and mount it
@@ -2084,12 +2084,12 @@ function delete($event_name, $data) {
 				foreach($log_folders as $log_folder){
 					//if($app->system->is_mounted($data['old']['document_root'].'/'.$log_folder)) exec('umount '.escapeshellarg($data['old']['document_root'].'/'.$log_folder));
 					//exec('fuser -km '.escapeshellarg($data['old']['document_root'].'/'.$log_folder).' 2>/dev/null');
-					exec('umount '.escapeshellarg($data['old']['document_root'].'/'.$log_folder).' 2>/dev/null');
+					exec('umount -l '.escapeshellarg($data['old']['document_root'].'/'.$log_folder));
 				}
 			} else {
 				//if($app->system->is_mounted($data['old']['document_root'].'/'.$log_folder)) exec('umount '.escapeshellarg($data['old']['document_root'].'/'.$log_folder));
 				//exec('fuser -km '.escapeshellarg($data['old']['document_root'].'/'.$log_folder).' 2>/dev/null');
-				exec('umount '.escapeshellarg($data['old']['document_root'].'/'.$log_folder).' 2>/dev/null');
+				exec('umount -l '.escapeshellarg($data['old']['document_root'].'/'.$log_folder));
 			}
 
 			// remove letsencrypt if it exists (renew will always fail otherwise)