Fix grammar in error string

Author: Mark Roberts

kafka/common.py

@@ -60,7 +60,7 @@
     7 : 'REQUEST_TIMED_OUT',
     8 : 'BROKER_NOT_AVAILABLE',
     9 : 'REPLICA_NOT_AVAILABLE',
-    10 : 'MESSAGE_SIZE_TO_LARGE',
+    10 : 'MESSAGE_SIZE_TOO_LARGE',
     11 : 'STALE_CONTROLLER_EPOCH',
     12 : 'OFFSET_METADATA_TOO_LARGE',
 }