consistent rescan, fix help for -txindex defaulting true
prevent infiniloop while reconstructing aliases
this fixes -rescan (previously: hungup)
this bug was introduced in https://github.com/syscoin/syscoin/commit/65228986711dddf288d15ed05b2d7b2d46e66998#diff-cfe9e5456ba40db0f1c7f4fdd72ff393