fix: change dockerfile path

compose.yaml

@@ -37,7 +37,8 @@ services:
       - ./config:/usr/src/app/config:ro
       - fluxer_data:/usr/src/app/data
     build:
-      context: ./fluxer_server
+      context: .
+      dockerfile: fluxer_server/Dockerfile
       args:
         FLUXER_BUILD_CONFIG: |
           { "domain": { "base_domain": "${FLUXER_BASE_DOMAIN}", "static_cdn_domain": "fluxerstatic.com", "public_scheme": "https", "public_port": 443 } }