Only disable auto-commit if we appear to need to.

git-svn-id: https://samskivert.googlecode.com/svn/trunk@2450 6335cc39-0255-0410-8fd6-9bcaacd3b74c

src/java/com/samskivert/jdbc/SimpleRepository.java

@@ -164,7 +164,7 @@ public class SimpleRepository extends Repository
                 }
 
                 // turn off auto-commit
-                if (supportsTransactions) {
+                if (supportsTransactions && conn.getAutoCommit()) {
                     oldAutoCommit = conn.getAutoCommit();
                     conn.setAutoCommit(false);
                 }