added checks for incomplete downloads

update.sh

@@ -1,5 +1,10 @@
 #!/bin/bash
-rm -r nextcloud.old
+if test -f latest.tar.bz2; then
+    rm latest.tar.bz2    #Removes incomplete or old downloads
+fi
+if [ -d "nextcloud.old" ]; then
+    rm -r nextcloud.old    #Removes old version of nextcloud
+fi
 sudo -u www-data php nextcloud/occ maintenance:mode --on
 mv nextcloud nextcloud.old
 wget https://download.nextcloud.com/server/releases/latest.tar.bz2