Use SQL Server 2017 instead

Author: paulbalandan

.github/workflows/test-phpunit.yml

@@ -62,7 +62,7 @@ jobs:
           - 5432:5432
         options: --health-cmd=pg_isready --health-interval=10s --health-timeout=5s --health-retries=3
       mssql:
-        image: mcr.microsoft.com/mssql/server:2019-latest
+        image: mcr.microsoft.com/mssql/server:2017-latest
         env:
           SA_PASSWORD: 1Secure*Password1
           ACCEPT_EULA: Y