fix: correct indentation in spawner-api error handling

- Fixed indentation mismatch in error handling block
- Consistent with other build error blocks

install.sh

@@ -454,7 +454,7 @@ else
     echo "  Letzte 50 Zeilen:"
     tail -50 "${BUILD_LOG}"
     exit 1
-    fi
+fi
 
 # Frontend Image bauen
 if [ -d "${INSTALL_DIR}/frontend" ]; then