disable store debug option in default config

contrib/sample-cfg.yaml

@@ -21,7 +21,7 @@ store:
     ## mysql: utf8mb4, utf8, ...
     ## will be ignored for postgres which will always use utf8 (1-4 bytes)
     charset: utf8mb4
-    debug: true
+    debug: false
 
 importer:
   temp-path: "/tmp"