Fix exception message check in Zend_Db_Table_TestCommon::testTableExceptionNoPrimaryKey

Fix exception message check in Zend_Db_Table_TestCommon::testTableExceptionNoPrimaryKey, which checks output of [this exception throw](https://github.com/zendframework/zf1/blob/master/library/Zend/Db/Table/Abstract.php#L889)

```
1) Zend_Db_Table_Pdo_MysqlTest::testTableExceptionNoPrimaryKey
Failed asserting that two strings are equal.
--- Expected
+++ Actual
@@ @@
-A table must have a primary key, but none was found
+A table must have a primary key, but none was found for table 'zfnoprimarykey'
```