[fix] Dockerfile: searx version stores in org.label-schema.version (#1659)

instead of org.label-schema.schema-version

Dockerfile

@@ -69,7 +69,7 @@ LABEL maintainer="searx <https://github.com/asciimoo/searx>" \
       version="${SEARX_GIT_VERSION}" \
       org.label-schema.schema-version="1.0" \
       org.label-schema.name="searx" \
-      org.label-schema.schema-version="${SEARX_GIT_VERSION}" \
+      org.label-schema.version="${SEARX_GIT_VERSION}" \
       org.label-schema.url="${LABEL_VCS_URL}" \
       org.label-schema.vcs-ref=${LABEL_VCS_REF} \
       org.label-schema.vcs-url=${LABEL_VCS_URL} \