patch 8.2.3272: cannot use id zero with prop_find()

Problem:    Cannot use id zero with prop_find(). (Naohiro Ono)
Solution:   Also accept id zero.
diff --git a/src/textprop.c b/src/textprop.c
index e5cc366..6c9d5c8 100644
--- a/src/textprop.c
+++ b/src/textprop.c
@@ -689,7 +689,7 @@
     if (dict_find(dict, (char_u *)"id", -1) != NULL)
     {
 	id = dict_get_number(dict, (char_u *)"id");
-	id_found = id != 0;
+	id_found = TRUE;
     }
     if (dict_find(dict, (char_u *)"type", -1))
     {