patch 8.2.4167: Vim9: error message for old style import

Problem:    Vim9: error message for old style import.
Solution:   Use another error message.  Add a test.
diff --git a/src/evalvars.c b/src/evalvars.c
index 15999bc..ca7e7e8 100644
--- a/src/evalvars.c
+++ b/src/evalvars.c
@@ -2711,7 +2711,7 @@
 		else
 		{
 		    if (flags & EVAL_VAR_VERBOSE)
-			emsg(_(e_import_as_name_not_supported_here));
+			semsg(_(e_expected_dot_after_name_str), name);
 		    ret = FAIL;
 		}
 	    }