entrypoint.sh: ignore Server Error responses (#56)

as these are temporary problems it's safe to assume that
retrying it at a later point resolve the issue

Closes #55

entrypoint.sh

@@ -101,7 +101,11 @@ api() {
     echo >&2 "api failed:"
     echo >&2 "path: $path"
     echo >&2 "response: $response"
-    exit 1
+    if [[ "$response" == *'"Server Error"'* ]]; then 
+      echo "Server error - trying again"
+    else
+      exit 1
+    fi
   fi
 }