fix alpine nightly build

package.json

@@ -26,7 +26,7 @@
         "build-docker-alpine": "docker buildx build -f dockerfile-alpine --platform linux/amd64,linux/arm64,linux/arm/v7 -t louislam/uptime-kuma:alpine -t louislam/uptime-kuma:1-alpine -t louislam/uptime-kuma:1.6.0-alpine --target release . --push",
         "build-docker-debian": "docker buildx build --platform linux/amd64,linux/arm64,linux/arm/v7 -t louislam/uptime-kuma -t louislam/uptime-kuma:1 -t louislam/uptime-kuma:1.6.0 -t louislam/uptime-kuma:debian -t louislam/uptime-kuma:1-debian -t louislam/uptime-kuma:1.6.0-debian --target release . --push",
         "build-docker-nightly": "docker buildx build --platform linux/amd64,linux/arm64,linux/arm/v7 -t louislam/uptime-kuma:nightly --target nightly . --push",
-        "build-docker-nightly-alpine": "docker buildx build --platform linux/amd64,linux/arm64,linux/arm/v7 -t louislam/uptime-kuma:nightly-alpine --target nightly . --push",
+        "build-docker-nightly-alpine": "docker buildx build -f dockerfile-alpine --platform linux/amd64,linux/arm64,linux/arm/v7 -t louislam/uptime-kuma:nightly-alpine --target nightly . --push",
         "build-docker-nightly-amd64": "docker buildx build --platform linux/amd64 -t louislam/uptime-kuma:nightly-amd64 --target nightly . --push --progress plain",
         "setup": "git checkout 1.6.0 && npm install --legacy-peer-deps && node node_modules/esbuild/install.js && npm run build && npm prune",
         "update-version": "node extra/update-version.js",