Add dialog asking to continue with download

src/freedombone-app-keyserver

 }
 
 function keyserver_import_keys {
+    dialog --title $"Import public keys database" \
+           --backtitle $"Freedombone Control Panel" \
+           --defaultno \
+           --yesno $"\nThis will download multiple gigabytes of data and so will take a long time.\n\nContinue?" 10 60
+    sel=$?
+    case $sel in
+        1) return;;
+        255) return;;
+    esac
     if [ ! -d /var/lib/sks/dump ]; then
         mkdir -p /var/lib/sks/dump
     fi
     cd /var/lib/sks/dump
-    echo $'Getting keyserver dump. This may take a few hours, so be patient.'
+    echo $'Getting keyserver dump. This may take a few hours or longer, so be patient.'
     wget -crp -e robots=off --level=1 --cut-dirs=3 -nH \
          -A pgp,txt $KEYSERVER_DUMP_URL
 
         dialog --backtitle $"Freedombone Control Panel" \
                --title $"SKS Keyserver" \
                --radiolist $"Choose an operation:" 10 70 2 \
-               1 $"Import keys database" off \
+               1 $"Import public keys database" off \
                2 $"Exit" on 2> $data
         sel=$?
         case $sel in