fix: Correct environment variable name (#6184)

Co-authored-by: liuzhenghua-jk <liuzhenghua-jk@360shuke.com>

docker-legacy/docker-compose.yaml

       # The default value is 300 seconds.
       FILES_ACCESS_TIMEOUT: 300
       # The maximum number of active requests for the application, where 0 means unlimited, should be a non-negative integer.
-      APP_MAX_ACTIVE_REQUESTS: ${FILES_ACCESS_TIMEOUT:-0}
+      APP_MAX_ACTIVE_REQUESTS: 0
       # When enabled, migrations will be executed prior to application startup and the application will start after the migrations have completed.
       MIGRATION_ENABLED: 'true'
       # The configurations of postgres database connection.

docker/docker-compose.yaml

   OPENAI_API_BASE: ${OPENAI_API_BASE:-https://api.openai.com/v1}
   FILES_URL: ${FILES_URL:-}
   FILES_ACCESS_TIMEOUT: ${FILES_ACCESS_TIMEOUT:-300}
-  APP_MAX_ACTIVE_REQUESTS: ${FILES_ACCESS_TIMEOUT:-0}
+  APP_MAX_ACTIVE_REQUESTS: ${APP_MAX_ACTIVE_REQUESTS:-0}
   MIGRATION_ENABLED: ${MIGRATION_ENABLED:-true}
   DEPLOY_ENV: ${DEPLOY_ENV:-PRODUCTION}
   DIFY_BIND_ADDRESS: ${DIFY_BIND_ADDRESS:-0.0.0.0}