Fix typo.

Author: Cito

DBUtils/PersistentPg.py

@@ -76,7 +76,7 @@
 begin() method. This ensures that the transparent reopening will be
 suspended until the end of the transaction, and that the connection
 will be rolled back before being reused in the same thread. To end
-transactions, use on of the end(), commit() or rollback() methods.
+transactions, use one of the end(), commit() or rollback() methods.
 
 By setting the threadlocal parameter to threading.local, getting
 connections may become a bit faster, but this may not work in all

DBUtils/PooledPg.py

@@ -87,7 +87,7 @@
 begin() method. This ensures that the transparent reopening will be
 suspended until the end of the transaction, and that the connection will
 be rolled back before being given back to the connection pool. To end
-transactions, use on of the end(), commit() or rollback() methods.
+transactions, use one of the end(), commit() or rollback() methods.
 
 
 Ideas for improvement: