Remove keyserver log files before backup

src/freedombone-app-keyserver

 }
 
 function backup_local_keyserver {
+    # remove any unused log files
+    cd /var/lib/sks/DB
+    db_archive -d
+
     source_directory=/etc/sks
     if [ -d $source_directory ]; then
         systemctl stop sks
 }
 
 function backup_remote_keyserver {
+    # remove any unused log files
+    cd /var/lib/sks/DB
+    db_archive -d
+
     source_directory=/etc/sks
     if [ -d $source_directory ]; then
         systemctl stop sks