Update Dockerfile

Dockerfile

@@ -18,7 +18,7 @@ ARG PNGX_TAG_VERSION
 # Add the tag to the environment file if its a tagged dev build
 RUN set -eux && \
 if [ ! -z "${PNGX_TAG_VERSION}" ] && [ "${PNGX_TAG_VERSION}" != "latest" ]; then \
-  sed -i "s/version: '([0-9\.]+)'/version: '\1 #${PNGX_TAG_VERSION}'/g" /src/src-ui/src/environments/environment.prod.ts; \
+  sed -i -E "s/version: '([0-9\.]+)'/version: '\1 #${PNGX_TAG_VERSION}'/g" /src/src-ui/src/environments/environment.prod.ts; \
 fi
 
 RUN set -eux \