In radioctl convert added check for existing ogg file.

tools/radioctl

@@ -23,6 +23,9 @@ case $1 in
             if [[ "$file" == *.ogg ]]; then
                 continue;
             fi
+            if [ -f "${file%.*}.ogg" ]; then
+                continue;
+            fi
             ffmpeg -hide_banner -i "$file" -y -vn -c:a libvorbis -b:a 128k "${file%.*}.ogg";
             if [ $? -eq 0 ] && [ $3 = "del" ]; then
                 rm "$file";