Change download folder to sub folder in this script

Also check if target gitea file exists and abort if not

init.sh

@@ -15,12 +15,16 @@ else
 	exit;
 fi;
 arch="linux-${CPU_ARCH}";
-download_folder="/opt/downloads/gitea/";
+download_folder="${BASE_FOLDER}download/";
 if [ ! -d "${download_folder}" ]; then
 	echo "Download folder ${download_folder} missing";
 	exit;
 fi;
 target_file="/usr/local/bin/gitea";
+if [ ! -f "${target_file}" ]; then
+	echo "There is no gitea target file at ${target_file}. Is gitea installed?";
+	exit;
+fi;
 
 export arch target_file;