set log level to WARNING to cut down on the chatter

rootfs/var/lib/synapse/log.config

@@ -10,26 +10,17 @@ filters:
     request: ""
 
 handlers:
-  file:
-    class: logging.handlers.RotatingFileHandler
-    formatter: precise
-    filename: /var/lib/synapse/homeserver.log
-    maxBytes: 104857600
-    backupCount: 10
-    filters: [context]
-    level: INFO
   console:
     class: logging.StreamHandler
     formatter: precise
 
 loggers:
     synapse:
-        level: INFO
+        level: WARNING
 
     synapse.storage.SQL:
-        level: INFO
+        level: WARNING
 
 root:
-    level: INFO
-    handlers: [file, console]
-    
+    level: WARNING
+    handlers: [console]