lock caddy version to 2.10 to fix docker buiilds

Author: Onatcer

docker/prod/Dockerfile

@@ -16,7 +16,7 @@ RUN CGO_ENABLED=1 \
     XCADDY_GO_BUILD_FLAGS="-ldflags='-w -s' -tags=nobadger,nomysql,nopgx" \
     CGO_CFLAGS=$(php-config --includes) \
     CGO_LDFLAGS="$(php-config --ldflags) $(php-config --libs)" \
-    xcaddy build \
+    xcaddy build v2.10.0 \
         --output /usr/local/bin/frankenphp \
         --with github.com/dunglas/frankenphp=./ \
         --with github.com/dunglas/frankenphp/caddy=./caddy/ \