[QPID-8257] Support empty messages with Sybase message store

This closes #14
https://github.com/apache/qpid-broker-j/pull/14
diff --git a/broker-plugins/jdbc-store/src/main/java/org/apache/qpid/server/store/jdbc/JDBCDetails.java b/broker-plugins/jdbc-store/src/main/java/org/apache/qpid/server/store/jdbc/JDBCDetails.java
index 6f374a5..b97269f 100644
--- a/broker-plugins/jdbc-store/src/main/java/org/apache/qpid/server/store/jdbc/JDBCDetails.java
+++ b/broker-plugins/jdbc-store/src/main/java/org/apache/qpid/server/store/jdbc/JDBCDetails.java
@@ -59,7 +59,7 @@
                 false, false);
         private static final JDBCDetails ORACLE = new KnownJDBCDetails("oracle", "blob", "raw(%d)", "number", "timestamp",
                 false, true);
-        private static final JDBCDetails SYBASE = new KnownJDBCDetails("sybase", "image", "varbinary(%d)", "bigint", "datetime",
+        private static final JDBCDetails SYBASE = new KnownJDBCDetails("sybase", "image null", "varbinary(%d)", "bigint", "datetime",
                 false, true);
         private static final JDBCDetails POSTGRES = new KnownJDBCDetails("postgresql", "bytea", "bytea", "bigint", "timestamp",
                 true, true);