fix spelling.

h2/src/docsrc/help/help.csv

@@ -1259,7 +1259,7 @@ SET MAX_LOG_SIZE int
 ","
 Sets the maximum size of the transaction log, in megabytes.
 If the log is larger, and if there is no open transaction, the transaction log is truncated.
-If there is an option transaction, the transaction log will continue to grow however.
+If there is an open transaction, the transaction log will continue to grow however.
 The default max size is 16 MB.
 This setting has no effect for in-memory databases.