patch 8.1.2166: rubyeval() not tested as a method

Problem:    Rubyeval() not tested as a method.
Solution:   Change a test case.
diff --git a/src/testdir/test_ruby.vim b/src/testdir/test_ruby.vim
index f679bbd..8f83a30 100644
--- a/src/testdir/test_ruby.vim
+++ b/src/testdir/test_ruby.vim
@@ -46,7 +46,7 @@
   " Check that movement after setting cursor position keeps current column.
   normal j
   call assert_equal([2, 6], [line('.'), col('.')])
-  call assert_equal([2, 5], rubyeval('$curwin.cursor'))
+  call assert_equal([2, 5], '$curwin.cursor'->rubyeval())
 
   call assert_fails('ruby $curwin.cursor = [1]',
         \           'ArgumentError: array length must be 2')
diff --git a/src/version.c b/src/version.c
index e7ba706..c7d0ace 100644
--- a/src/version.c
+++ b/src/version.c
@@ -754,6 +754,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    2166,
+/**/
     2165,
 /**/
     2164,