Fix null check in getTablePrivileges

The null check to report the owner as grantor if it's missing is
broken.

org/postgresql/jdbc2/AbstractJdbc2DatabaseMetaData.java

@@ -2866,7 +2866,7 @@ else if (connection.haveMinimumServerVersion(ServerVersion.v7_3))
                    for (Object grant : grants) {
                        String[] grantTuple = (String[]) grant;
                        // report the owner as grantor if it's missing
                        String grantor = grantTuple[0].equals(null) ? owner : grantTuple[0];
                        String grantor = grantTuple[0] == null ? owner : grantTuple[0];
                        // owner always has grant privileges
                        String grantable = owner.equals(grantee) ? "YES" : grantTuple[1];
                        byte[][] tuple = new byte[7][];