Fix variable definition (#13226)

Author: lystopad

Dockerfile.release

@@ -45,7 +45,7 @@ SHELL ["/bin/bash", "-c"]
 
 RUN --mount=type=bind,from=temporary,source=/tmp/${APPLICATION},target=/tmp/${APPLICATION} \
     echo Installing on ${TARGETOS} with variant ${TARGETVARIANT} && \
-    addgroup --gid {GID_ERIGON} ${GROUP} && \
+    addgroup --gid ${GID_ERIGON} ${GROUP} && \
     adduser --system --uid ${UID_ERIGON} --ingroup ${GROUP} --home /home/${USER} --shell /bin/bash ${USER} && \
     apt update -y && \
     apt install -y --no-install-recommends ca-certificates && \