server: make gunicorn friendly

server/host-waitress

@@ -10,7 +10,7 @@ import argparse
 import os.path
 import sys
 import waitress
-from szurubooru.facade import create_app
+from szurubooru.facade import app
 
 def main():
     parser = argparse.ArgumentParser('Starts szurubooru using waitress.')
@@ -19,7 +19,6 @@ def main():
     parser.add_argument('--host', help='IP to listen on', default='0.0.0.0')
     args = parser.parse_args()
 
-    app = create_app()
     waitress.serve(app, host=args.host, port=args.port)
 
 if __name__ == '__main__':

server/szurubooru/facade.py

@@ -113,3 +113,6 @@ def create_app():
     rest.errors.handle(sqlalchemy.orm.exc.StaleDataError, _on_stale_data_error)
 
     return rest.application
+
+
+app = create_app()