patch 8.2.4930: interpolated string expression requires escaping

Problem:    Interpolated string expression requires escaping.
Solution:   Do not require escaping in the expression.
diff --git a/src/dict.c b/src/dict.c
index 88cc4b3..538dd8b 100644
--- a/src/dict.c
+++ b/src/dict.c
@@ -866,13 +866,13 @@
 
     if (**arg == '\'')
     {
-	if (eval_lit_string(arg, &rettv, TRUE) == FAIL)
+	if (eval_lit_string(arg, &rettv, TRUE, FALSE) == FAIL)
 	    return NULL;
 	key = rettv.vval.v_string;
     }
     else if (**arg == '"')
     {
-	if (eval_string(arg, &rettv, TRUE) == FAIL)
+	if (eval_string(arg, &rettv, TRUE, FALSE) == FAIL)
 	    return NULL;
 	key = rettv.vval.v_string;
     }