patch 9.0.0219: cannot make a funcref with "s:func" in a def function

Problem:    Cannot make a funcref with "s:func" in a def function in legacy
            script.
Solution:   Allow for using a lower case function name after "s:". (Kota Kato,
            closes #10926)
diff --git a/src/vim9expr.c b/src/vim9expr.c
index b2bb405..8cd095c 100644
--- a/src/vim9expr.c
+++ b/src/vim9expr.c
@@ -8,7 +8,7 @@
  */
 
 /*
- * vim9cmds.c: Dealing with compiled function expressions
+ * vim9expr.c: Dealing with compiled function expressions
  */
 
 #define USING_FLOAT_STUFF
@@ -451,8 +451,7 @@
 			      vim_free(name);
 			      return FAIL;
 			  }
-			  if (is_expr && ASCII_ISUPPER(*name)
-					     && find_func(name, FALSE) != NULL)
+			  if (is_expr && find_func(name, FALSE) != NULL)
 			      res = generate_funcref(cctx, name, FALSE);
 			  else
 			      res = compile_load_scriptvar(cctx, name,