patch 9.0.2087: build-failure in vim9class

Problem:  build-failure in vim9class
Solution: reference correct error message,
          disable non-failing test

closes: #13476
closes: #13477

Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/vim9class.c b/src/vim9class.c
index 08c3713..f709c1f 100644
--- a/src/vim9class.c
+++ b/src/vim9class.c
@@ -1560,7 +1560,7 @@
 	    p = skipwhite(pa + 8);
 	    if (STRNCMP(p, "def", 3) != 0 && STRNCMP(p, "static", 6) != 0)
 	    {
-		emsg(_(e_abstract_must_be_followed_by_def_or_static));
+		emsg(_(e_abstract_must_be_followed_by_def));
 		break;
 	    }