infra: Fix weird sed replacement result.

Author: intersectRaven

Dockerfile

@@ -158,7 +158,7 @@ RUN set -ex; \
     rm -rf /var/lib/apt/lists/*
 
 RUN sed -i 's/8.5/8.6/g' /usr/src/nextcloud/lib/versioncheck.php; \
-    sed -i 's/80500/80600/g' /usr/src/nextcloud/lib/versioncheck.php
+    sed -i 's/8.600/80600/g' /usr/src/nextcloud/lib/versioncheck.php
 
 COPY *.sh upgrade.exclude /
 COPY config/* /usr/src/nextcloud/config/