patch 8.2.4132: Vim9: wrong error message when autoload script can't be found

Problem:    Vim9: wrong error message when autoload script can't be found.
Solution:   Correct check for using autoload with wrong name.
diff --git a/src/testdir/test_vim9_import.vim b/src/testdir/test_vim9_import.vim
index 1353015..79c1ca4 100644
--- a/src/testdir/test_vim9_import.vim
+++ b/src/testdir/test_vim9_import.vim
@@ -1433,9 +1433,21 @@
 
   lines =<< trim END
       vim9script
-      import autoload 'doesNotExist.vim'
+      import autoload './doesNotExist.vim'
   END
   CheckScriptFailure(lines, 'E1264:')
+
+  lines =<< trim END
+      vim9script
+      import autoload '/dir/doesNotExist.vim'
+  END
+  CheckScriptFailure(lines, 'E1264:')
+
+  lines =<< trim END
+      vim9script
+      import autoload 'doesNotExist.vim'
+  END
+  CheckScriptFailure(lines, 'E1053: Could not import "doesNotExist.vim"')
 enddef
 
 " test disassembling an auto-loaded function starting with "debug"