Update sql-migration-guide.md

Author: imback82

docs/sql-migration-guide.md

@@ -340,6 +340,8 @@ license: |
 
   - Since Spark 3.0, `SHOW TBLPROPERTIES` on a temporary view will cause `AnalysisException`. In Spark version 2.4 and earlier, it returned an empty result.
 
+  - Since Spark 3.0, `SHOW TBLPROPERTIES` will cause `AnalysisException` if the table does not exist. In Spark version 2.4 and earlier, it caused `NoSuchTableException`.
+
 ## Upgrading from Spark SQL 2.4 to 2.4.1
 
   - The value of `spark.executor.heartbeatInterval`, when specified without units like "30" rather than "30s", was