Only delete logged apk

To avoid unintended deletion of apks only the apk logged as the old
version should be deleted. This will probably cause some backup
directories to have two apks during the first backup cycle after this
commit if the package has been updated in the meantime.

src/dk/jens/backup/BackupRestoreHelper.java

@@ -15,7 +15,14 @@ public static int backup(Context context, File backupDir, AppInfo appInfo, Shell
         if(!backupSubDir.exists())
             backupSubDir.mkdirs();
         else if(backupMode != AppInfo.MODE_DATA && appInfo.getSourceDir().length() > 0)
-            shellCommands.deleteOldApk(backupSubDir, appInfo.getSourceDir());
+        {
+            if(appInfo.getLogInfo() != null && appInfo.getLogInfo().getSourceDir().length() > 0 && !appInfo.getSourceDir().equals(appInfo.getLogInfo().getSourceDir()))
+            {
+                String apk = appInfo.getLogInfo().getApk();
+                if(apk != null)
+                    ShellCommands.deleteBackup(new File(backupSubDir, apk));
+            }
+        }
 
         if(appInfo.isSpecial())
         {