Update start.sh

start.sh

@@ -1,5 +1,13 @@
 #!/bin/bash
-git clone https://github.com/TwanAPI/BEupload.git .
-go install
-pwd
-go run main.go
+set -e
+
+cd /tmp
+
+if [ ! -d BEupload ]; then
+    git clone https://github.com/TwanAPI/BEupload.git
+fi
+
+cd BEupload
+
+go mod download
+go run .