patch 9.0.1198: abstract class not supported yet

Problem:    Abstract class not supported yet.
Solution:   Implement abstract class and add tests.
diff --git a/src/version.c b/src/version.c
index 52eabb5..763c79d 100644
--- a/src/version.c
+++ b/src/version.c
@@ -696,6 +696,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1198,
+/**/
     1197,
 /**/
     1196,