patch 8.2.2217: Vim9: command modifiers not restored in catch block

Problem:    Vim9: command modifiers not restored in catch block.
Solution:   Restore command modifiers. (closes #7542)

src/testdir/test_vim9_cmd.vim

@@ -546,6 +546,13 @@ def Test_modifier_silent_unsilent()
 
   silent EchoThere()
   assert_equal("\nthere", execute(':1messages'))
+
+  try
+    silent eval [][0]
+  catch
+    echomsg "caught"
+  endtry
+  assert_equal("\ncaught", execute(':1messages'))
 enddef
 
 def Test_range_after_command_modifier()