Proper syncronization on session to avoid concurrent connection usage

h2/src/main/org/h2/jdbc/JdbcConnection.java

@@ -453,10 +453,10 @@ public class JdbcConnection extends TraceObject
                 debugCode("setAutoCommit(" + autoCommit + ");");
             }
             checkClosed();
+            synchronized (session) {
                 if (autoCommit && !session.getAutoCommit()) {
                     commit();
                 }
-            synchronized (session) {
                 session.setAutoCommit(autoCommit);
             }
         } catch (Exception e) {